You have to ask yourself a few question. What venue are you planning to do the set for? How long of a set? How many people? Who are you as a performer? What message are you trying to convey? Once you get all that, you can figure out the tricks you want to do. Then, look at what presentations you use that can call back previous tricks or plots and put them in the right order so that they can flow correctly. Then, you're going to need to decide what your opener and closers are. The opener needs to immediately let people know that you have talent and deserve some attention. You're closer needs to be the strongest trick in the set, wrap up the show, and look like a finale. In a card set, something like David Regal's Disposable Deck is a great closer because the entire pack is destroyed at the end. Now of course this is all for a formal set.
If you're just wanting to do a couple of tricks for walk around show, ignore this for now and just do the tricks you think will get the best reaction and are ENTERTAINING. Remember, the tricks aren't nearly as important as your connection with the audience. You're job is to entertain them, not show off how good you are. There's a big difference. My walk around set is never all cards, either. Generally my set is made up based on the audience. I usually keep it to about 3 tricks/10 minutes, unless it's a good group, which makes me feel better, so I stay a few extra minutes. Off the top of my head, I would use a coin trick to open, because it's not a card trick and everyone likes money, then a card trick, and close with Liquid Metal or a Card to Wallet.