You can find a nice list of idioms here if you need some ideas. Here's a good example of what I mean, created by `zacthetoad. This is "jumping on the bandwagon":
The rules are simple:
1. The emote must be a literal representation of the idiom
2. You must link me to your entry via note or journal comment.
3. The deadline for all entries is August 8, 2007.
You can submit as many entries as you wish, animated or static, small or large.
The prizes are not so simple:
1. 1 one-year subscription or print of equal value for first place.
2. 1 six-month sub or print of equal value for second.
3. 1 three-month sub or print of equal value for third.
4-14. 10 one-month subs as special awards.
Special awards include:
Most detailed, most disconcerting, most obscure idiom, most cruel to cartoon animals, most kind to cartoon animals, most funny, and more we haven't thought of yet.
The judges are myself, `darkmoon3636, `LawrenceDeDark, and ~MissM69. Check this journal to see a full list of the current entries.
So, get idioming!