We always tidy before we change activities... clean up then circle time, clean up then lunch etc. It usually keeps them motivated. We do this 4 - 5 times per day.

Oh and to op, in my opinion a little on under 2 is quite capable of cleaning up I do the same as E4Guppies, give specific jobs to sepcific children. Dc1 pick up the rings, dc2 pick up the dressup clothes, dc3 tidy up the cars....