I have a 1, 2, 3 and you're in time out. It seems to work with my toddlers. You just say:

1 J, please pick up the toys. 2 J, do you need help with picking up the toys? 3. Ok, let's pick up the toys, and then you go in time out.

If you nip it in the bud right away, they'll get the point.

For example if they hit or bit a child, I would attend to the 'victim', and then be stern and put the child that bit/hit in time out. Not long, but long enough to get the point. Give them a stern, disappointed look (that usually kills them!). Once they're 'done' in time-out, explain to the child what they did wrong, and what to do the next time.

Hopefully that helps!