I normally don't allow them in my sewing room. one is let in occasionally because he just lays on my computer desk or in my chair. the other two just get into everything. i had one once that tried to "catch" the needle as it went up and down. i was scared that she would hurt her paw so i chased her out.
We use a pop can with pennies in it. Shake it hard and say no. the trick in training is to make it uncomfortable enough for them that it sticks in their mind-i didn't like that spot. Our first couple of cats were bathed in the kitchen sink-even if you were holding them and ventured too close, they would claw and scrabble to get away. one had jumped up on the stove after the burners were off but still hot(unknown to us til we saw her paw kind of peeling) She wouldn't get anywhere near there. the can seems to work for tables and such-if you see them, but i have one that likes to stretch out with her claws in the furniture corners. haven't been able to break her of that yet. Darn!