Tips for Trading Coupons?

You 1st need to build your reputation. Go to hotcouponworld.com. In the forums section you can register and go to the trades section.
Make a list of coupons you have to trade and a list of coupons you would like in return. Post that on the trades section.

One way to build your reputation is to offer ROAK (Random ACT Of Kindness) Offer coupons free of charge in exchange most people will rate you as a trustworthy trader. The more trades you do the better your reputation and the easier it is to do trades.
You can also join a coupon train. The train starts with a conductor who has people sign up for the train. The conductor makes a list of names and addresses of each person who has signed up. They send and envelope with 50 or so coupons to the 1st person. The 1st person takes the coupons they want and replaces what they took before sending it to the next person. It goes through the list until it is returned to the conductor by the last person. After it has run a full round each member can decide if they would like to get off the train or keep on riding another round.
I have been on good trains but I have also been on trains where people are jerks and just put in coupons for things like hemorrhoid cream and flea powder etc.