When my grandson reached that stage, we instituted a rule that only one toy at a time be brought out. We also helped him (several times a day) to clean up the stuff already lying around as if it were the most fun we could possibly have, and would cheerfully sing our clean-up song:
Clean up, clean up, everybody clean up;
Everybody everywhere, everybody do your share!
(Make up your own tune and repeat until the job is done.)
Attitude is everything, at any age. If cleanup is just an integral part of keeping life fun, safe and organized, there is no need to see it as a separate, objectionable task. Yes, it's draining to have to keep helping our little ones learn essential tasks. The repetition can feel oppressive; UNLESS we remember why we do it and that this is the reality we chose.
Of course, we can do this the "usual" way, too, with rewards and punishments, charts, yelling or nagging, begging, arguments, constant annoyance and disappointment, teaching our kids that work is unappealing…