As parents we do tend to say the word no often. So, I have found that I save the word no for important things that will hurt the child if they continue to do it. I will use uh-ohs for other things that I just don't want them to play with. For example, playing the piano---not really something that will hurt him, but I don't want sticky fingers on the keys---so a uh-oh's and push the hands away and redirect to something else. If it is something that they are constantly into and you don't want them to be, if you can move it, put it somewhere where they can't get to it and be tempted. Something else is to find a room where there is appropriate things to play with and be into, and get a gate---when you really need a few minutes uninterrupted like when fixing dinner---and lock him in there. Then you know there isn't anything that will hurt him, everything is safe to explore and you can finish dinner. A friend of mine also has one drawer in the kitchen that has safe things in it that the children can play in without being told no. She has filled it with all the little toys you can get in the kids meals at fast food places. This gives them one spot to explore in the kitchen. Hope that this helps.
J.--SAHM of 6