A good hat is a good idea...
Hiking
My needs and environment are very different from yours, but here are some tips.
Keep a text list and modify it as you go. This is how you learn and improve.
Mount the stuff you find yourself using the most, or want to get to quickly, on the top of your pack's straps. For me that's a cheap knife, compass, monocular, reading glasses, extra gun magazine. Gun is of course optional, I don't know what it's like where you're at, nor the laws. Probably not a lot of bears, panthers or gators in the Austin area! But remember, 2-legged threats and crazy asshole dogs are more realistic problems. In any case, I sometimes pop off a few for fun. Don't forget ear pro!
Here's my overland gear, and me looking like a dork. There may be some ideas here for you.
- Emergency whistle
- eBay mag pouch for the monocular and small flashlight
- Olight flashlight on the chest band (extra lights inside)
- Casio watch. Super cheap, super tough. Just got one with tide and moon predictions! And there's one for $45 on eBay that has a compass and temperature sensor.
- Extra cold weather clothes like the neck gaiter and gloves. (I had just got home from the cold.) Also pack a hat for warmth, sun or rain, depending.
- First aid kit with bandages, gauze, antibiotic goo, etc. Pills like Tylenol and allergy and kratom. You do you.
- A camp towel is super nice!
- Use molle gear! It's the standard system for attaching goodies that the military uses. Pouches, clips, whatever are cheap on eBay. Just added a smallish pouch to me waist strap. Very nice for temp storage.
- There's a flare and emergency beacon in the the back for OMG-broken-leg issues. Lot's of military craft overhead around here, may not help you much.
- Extra food like nuts, protein bars, jerky, etc. That really saves me on most trips!
- Small thrift-store cooler for beer. Just discovered that freezer packs are far better than ice!
- Thrift store boots and my god did I luck out. $7 and those are the most comfortable and warm boots I've ever had, day one. And no, they weren't broken in at all, very new. They're what I call "duck boots", good for swampy terrain. I can vouch for these combat boots for dry terrain. And these socks have lasted me 5-years.
- A handful of carabiners and a little paracord goes a long way.
- Trash bags should be at the top of this list. Take Walmart style bags, fold them over 3 times, burp the air out, roll tight, rubber band. Pro tip: Grab the trash you find on the way out. No use packing it both ways.
- Lots of hair ties! So very useful in the field! Think: Tough rubber bands. Thin Velcro straps are nice as well.
- Tiny and flat space blanket and poncho, in case I'm caught after dark and have to tough it.
- Lighter and a small container of dried napalm. Nothing is so fine to start a campfire! Stuff unleaded and styrofoam in a pickle jar, dry on a cookie sheet, chop into little bits.
Above ALL things, your gear must be comfortable. Can you run, climb and jump in it? What if you get all screwed up and have to walk 20 miles? Anything rubbing, even the tiniest bit? For example: See how my gun is mounted? The barrel barely clears my elbow as I walk. Don't put up with anything even mildly annoying. That shit adds up fast.
I'm a little top heavy (tall, but relatively short legs), which makes steep descents no fun at all - and having a handy stick / hiking pole makes a huge difference for me.
Obviously this will depend on both your terrain and your build.
Beginner hikers always either overplan or underplan.
For day hikes under 10miles I wouldn't even wear hiking boots unless they're well broken in -- rather go with comfortable runners that are well broken in. Unless you're working on breaking in your hiking boots, the blisters are usually worse than the advantages the boots will give you.
After that, my basic day hike kit is: cell phone, water (volume depends on temperature), light snacks, basic safety kit, sun screen and bug spray. Dress to the weather forecast. If it's wooded, sunglasses that wrap around keeps the branches out of the eyes.
I use my cell phone for navigation and maps and photos, and just make sure it is fully charged before departure. If I'm expecting a particular long day, I will turn my cell phone to airplane mode to save battery.
My emergency kit consists of: a lighter, a multi tool, and a very small first aid kit. The most important things in the first aid kit are compression bandages, in my opinion -- your worst case scenario is something like a twisted knee where you can bind it up and still get out. Anything worse and you're calling 911 anyway.
In my neck of the woods, bear spray is also typical, but probably won't be near Austin.
I don't worry about what my water is packed in. I usually use a nalgene bottle or a couple of disposable bottles. I don't see the real advantage that the bladders offer until you get to the extreme version of hiking. If you are running a 30 mile trail, this would be a different story.
My SO does the multi-day version of hiking with some hiking buddies. She packs quite differently because weight becomes much more important if you're taking your camp with you. Then you start measuring calorie-density and packing water purification equipment and such. But you will absolutely not need to do any of that kind of stuff unless this is training for overnight hiking.
This post is almost exactly what I'd write!
I'll add that my first aid kit always includes water purification tabs like Aquatabs and I throw in a light windbreaker or rain jacket if the hike will be more than a half day or in a very low traffic area.
In the west/southwest, you want a bladder for the volume. Even a half gallon is insufficient for a day hike. I wouldn't go out without 1.5-2 gallons per person for a day, typically by having a 1.5 gal bladder and a couple bottles. Lack of moisture in the air means more sun exposure and greater water loss just breathing.
And you quickly lose cell coverage in the west once you leave a city. So any phone will eat battery unless in airplane mode, which also shuts off GPS. I just turn my phone off in such places, and save it for emergency use. I also carry a small external battery.
A compact GMRS radio (and knowing the local channels/repeaters) would be a great thing in the hiking world. Lots of volunteer folks use them when they're out hiking/4 wheeling, and can provide a link to emergency services. There are even Android-based units with GPS and data capabilities (for sending your location over GMRS) today.
Really good points about the first aid kit/compression bandages. You need the kinds of things that will get out out of a bad situation, not necessarily as much for minor things (tape will do for most cuts).
I think too many people step into longer hikes before doing shorter ones, where you'd get a chance to work out your boots and gear. Though my day pack is on the excessive side, but I see it as a "rucking" opportunity - it's only a day, so it's good exercise for me.
I haven't spent a lot of time in hot desert... Six weeks in the Atacama though, but it is rarely above 25C there. The rest of my hot weather experience is in humid climates. So I'm not really sure what my water churn would be for a day hike near Austin.
Based on OPs provided info: For a day hike under ten miles, provided you aren't "rucking" or pushing the pace to much, you can get by without measuring in gallons most of the time. If it's super hot, schedule your hike early or late.
Also, mirroring the other comment: phone GPS definitely works in airplane mode.
Bonus photo: mineral exploration in the Atacama.
I see where you're coming from with a lot of this, but I want to clarify a few points that i think are more about personal style.
I hike with two random 1l water bottles in my backpack's side pockets and a 2l pouch / flexible bottle inside that can be ignored or filled depending on how much water is in the area. I have another 2l pouch to add for longer/dryer trips. It's a great system for me because I can always track what I use by knowing what's left on the outside and whether there's a full refill or two inside.
I think you're wrong on phone use. I use Garmin Explore because I have an Inreach, but Gaia, Alltrails, Caltopo, BCNav, etc. all let you download maps to use offline, then use with your phone in airplane mode but with the GPS on (yes, you can do that).
A fully featured swiss army-like knife...with saw and tweezers
Try different hiking boots, given it's the southwest you'll probably want the lighter, goretex kind. Break them in first by wearing them around town occasionally.
For even short day hikes in the west/southwest, it's hard to carry too much water - when I've hiked the west, I've rarely come home with leftover water, and I have a large camelback.
Don't hike in shorts or short sleeves, sun exposure is brutal in the west. There's a reason western hats and sombreros have large brims - find one you like.
Think about what's needed if you have to stay out overnight. There are stories every year of people needing to be rescued because they couldn't get back for relatively minor reasons (e.g. Twisted an ankle). Having a little gear for that, just in case, can make a real difference.
A compact GMRS radio (and knowing the local channels/repeaters) can also help where cell coverage is spotty (the west in general, especially hiking areas).