Here are some tips:
- wear bright colors: blue is good, bright grey, white with jeans, a colorful scarf maybe
- your face must be visible. No sunglasses or hats
- make your backpack visible: place it infront of you, so people can see it immediately
- and most important of course: stand in a place where its easy to stop and where traffic does not go too fast (max 60 is good)
How you look is important when standing next to the road. Are you concentrated on what you are doing? Don´t hide anything, don´t fiddle with your waterbottle/luggage/cigarette when you are waiting for a lift. Sometimes you can hide it behind the panel, but if drivers see that you are doing something else, they won´t take you seriously. If you really need some water, just step aside and do what you have to do, then get back to your space and continue holding your thumb and sign out. We all need a break sometimes.
Look trustworthy and smile relaxed. Yes, you are aware of what you are doing. There can be 100 cars passing by and expressing their distrust to you by honking. You dont care. You KNOW what you are doing and that you WANT to hitchhike. And you are friendly. A good talker and listener. So who wants some converstaional partner today? Let´s see who is passing by...
The road is calling! Good luck!