We generally want to use what is called "remote correction", meaning the cat will not know where the correction came from. This will help prevent the cat from displaying the behavior simply to get attention, or waiting until we are not around to correct him.
If we see the cat starting to jump up on the counter, we can throw a pop can filled with a few coins and taped shut, toward the cat. We do not want to hit the cat, but want to startle him so he stops what he is doing. This works fine if we are in the kitchen waiting for him, but how do we correct him when we are not around? This is where imagination comes in.
Placing cookie sheets filled with water on the counter will give the cat a very unpleasant experience the next time she tries jumping up there. A word of caution from my experience: Do not place the cookie sheets on the counter such that they hang over the edge. I unfortunately did this, plus filled them extra full. When my dear Eddie jumped up he hit the cookie sheet which landed on the floor along with a flood of water. He got off scot free and I spent the next 15 minutes mopping up the wreckage.
Balloons can be a festive deterrent. Blow up a balloon and let your cat sniff it, then pop it by the side of his head. If this is done several times, the cat will soon start to detest balloons, at which time you can decorate the edges of your counter with balloons. You could even color coordinate them with your decor!!
There are several devices available commercially which may be helpful. Large plastic devices which look like mousetraps can be placed on the counter and when the cat jumps on them, the paddle will slap making a loud scary noise.
There are also "scat mats" which will give the cat a small electric shock (like a carpet shock) when the cat jumps on them.
Finally, why does your cat jump up on the counter? If it is food that is enticing him, keep food off of the counter and put it in cupboards unless you are in the kitchen. If "fun things" are often on the counter - pens, paper bags, pieces of paper, etc., clear these off the counter as well. If the counter is near a window, close the curtains or pull down the shade so the cat can not use the counter as a vantage point for surveying his outside kingdom. Bottom line: if the counter is empty and boring, there will be no positive reinforcements (food, toys, view) for getting up on the counter. Simultaneously, increase the interest on ground level. Buy some new toys, but don't put them out all at once. Rotate which toys are out so they will seem more interesting and not the "same old thing". Set up some paper bags, cardboard boxes, etc. to allow a good game of hide and seek. Your imagination is hte only limiting factor!