Wear good walking shoes and have enough of socks. If they're waterproof, they can soak your socks after a day of walking, if they're really breathable, they can make socks last a week. Soggy socks leads to bootrot, nobody likes to have bootrot. Wool is wonderful.
A metal cup or a bean can is an awesome thing to have. It can be a cup, bowl, plate, cooking pot, percussion instrument, etc.
Always keep your gear with you, if you leave it, you could lose it.
When you're hitchhiking on interstates, putting your thumb out at on ramps is difficult and it's illegal in a lot of places and takes forever to get a ride. You can find a gas station next to the on ramp you want to hitch, ask people for a ride. Make sure you're on the side of the freeway going the direction you're going. If you try to hitchhike to Vancouver, WA when you're in Centralia, WA, but you're on the northbound side of I-5, you could end up going north and have a ways to back track.
There's a video on StP that shows how to make a camp stove out of a beer can, it blew my mind. I recommend you watch it because you'll probably use it and it's way cheaper/lighter/awesomer than buying some hoaky doaky green gas, fold up, coleman/REI/hightechwasteofmoney campstove. plus you can probably find a way to use it to dry wet clothes.
You can wash your clothes in a river (or a bucket of water. soap, then rinse) if you have laundry soap then hang it to dry on a clothes line (difficult/impossible in overcast or freezing weather). You can use Dr. Bronners and take a bath in the river (brrr cold, yet exhilarating, soap and scrub before you jump in if it's a polar bear dip), not worry about poisoning the fish and frog eggs down stream, and it smells wonderful (works as shampoo and soap for anything)
A marker is a credit card in dire times, otherwise you gotta spange. Sometimes you really want money, although, there are usually alternative options, but people skills are somewhat mandatory while living as a transient/vagrant in Babylon. Hustle helps, and you never have to lie.
If you brush your teeth before you talk to people, they won't be trying to escape your breath or distracted/disgusted by your teeth.
Watch yourself when you hitchhike. If you're pissy, you could be walking. If you get on your rides nerves, you could be walking. If you wipe a big booger on the carpet of their neat car, you could be walking. If you set a bad example to their kids, you could be walking. If you smell bad and they have asthma, you could be walking. Be mindful, maybe you can't cover all of your bases, but you can be considerate of others.
Hitchhiking is easier when you look like a bright person, with a bright attitude, and when you're wearing bright colors. You know when you're driving down the road at night and there's somebody walking on the road and you don't see them because they're wearing black and you almost hit them and swerve and are like "WOAH! That idiot's wearing dark colors at night!". Well you know when you're driving down the road and you see a blinking light off in the distance, as you get closer you notice two white shiny thingys bouncing up and down at a syncopated rhythm, you get closer and it gets brighter and then you see it's a jogger. You're like "Woah! I almost thought that was a tiny spaceship. That guy's smart!" Do you notice the difference between the two? That could've been the same person both times, could've been the same driver. The different reactions from the driver is caused by what the pedestrian is wearing. Bright colors count. During the day too, if you're wearing camo on the side of the road, good luck. Wear red and yellow or even a white shirt or whatever, you can get a ride quick. Plus, it's trendy for a lot of kids to dress with neon colors. I've also noticed kids tend to be less experienced and more generous (mostly, but not always).
Props get props. Bikers pick up bikers, skaters pick up skaters, smokers pick up smokers, if you're on an iphone you're fucked no matter what (ha! kidding). I don't know where I heard somebody say don't smoke while hitchhiking, I couldn't count how many times I would smoke cigs with my thumb out and somebody would stop and I would have to toss my cigarette.
Get used to camping. When looking for a place to sleep, get creative. I like using a tarp, tent stakes, a walking stick, and string to make a tent. It keeps you dry and can store stuff (bike, guitar) or people. You can just roll it out and lie on it, under the stars too. Bivy sacks are great, army surplus has cheap ones. I've tried blankets in place of sleeping bags, but you can't beat a comfy sleeping bag. think before you sleep, check for syringes, look around, make sure the tide won't wash you away, look up, see if any grape fruit, pinecones, widow makers, bird nests, are above you. If there's any of the such, you might want to consider that, take precautions, or move. Get to know the wildlife, bugs, birds, bees, hornets, bears, cougars, alligators, fire ants, spiders, rats, chupacabra. Keep your food packed tight so critters can't smell it. If critters can smell it, they could chew a hole in your pack to get it or worse, take your pack. Zip-lock baggies are handy for sealing food, waterproofing electronics, maps/papers. The further in the woods you get, be prepared, compass, map (gps isn't reliable enough, satellite network can go down, your software can go out of date, batteries can die, it can break, get wet, not find enough satellites for a 2d lock, I've worked extensively with GPS and curse their technological weaknesses endlessly), hatchet, lighter, metal cup or bean can, cell phone, food, people,