H.W.
It's great that your little one is so bright! I would wholeheartedly suggest looking into Positive Discipline techniques. Much of this involves giving children two positive choices and engaging them intellectually to help them come round to why a certain action may not be helpful/appropriate. An example of 2 positive choices might look like this: when my son was 2 years old and climbing on the table, I'd tell him 'You may keep your feet on the floor, or you may play in the living room" --no table there!-- instead of "Get off the table or you have time out". An example of intellectual engagement: when my son doesn't want to wear a coat, I can ask him to look out the window. "What is happening?" I ask. He notices it's raining. "Oh, yes, it is raining. What will happen if we go outside in the rain?" He says 'he'll get wet". "Yes, that's right, you will get wet. What do you think we should do to keep ourselves dry?" Bingo! He puts on the coat, because he's now on board with the idea.
This also works for picking up toys. Two things I've learned: one, the organizational aspect of this task often requires side-by-side work with the child. We are modeling this task for them, teaching them where things go, and they need a lot of repetition for this. I also explain to my son that his toys need to 'go night night', the importance of picking up things so "the vacuum cleaner won't suck them up", and I limit the amount of toys he has available... over half of them are stored elsewhere, and we rotate them in and out of his room. This is especially helpful, because he can be more independent in finding where they belong.
The biggest thing I have learned in my nearly 20 years of working with kids is that no matter what age, we can't punish them into developing good habits. We can help them (in example of the cleanup--being present to help and guide, not command; limiting the sheer volume of the potential mess, etc.) and there are sometimes natural consequences that present themselves from time to time. More often than not, however, we need to try to meet them on their level. So give the Positive Discipline a try. I don't think you'll regret it!