Others neatly cut fancy paper and emboss it with rubber stamps. There are no limits to the designs people make. You do not have to sign fb's if you don't want to, just pass it along to someone else. It is best not to make fbs too large because you don't want to pay too much for postage and have a hard time fitting them in envelopes. Friendship Sheets are just like fbs, but instead of a booklet format they are just one sheet of paper.
Slams are similar to fbs.
This is where you write in your name and address or stick your label, usually next to a number. On each of the following pages is a question. Under the question all the signers add their answer next to their number. Crams are fbs on a small scale. The point is to cram many address on to a small piece of paper.