"You may sit on the couch or you may stand on the floor". When the child stands on the couch, put him on the floor. "I see you want to stand up. You may stand up on the floor." Keep it short and sweet.
Laurie A. answered a post like this a few days ago, with lots of 'two positive choice' examples. Kids at this age, in my opinion, (I know, only mine and others will disagree... okay with me) don't benefit from punishment. They do better with guidance and instruction. Constant reinforcement of appropriate, safe choices is our job at this stage. I try to eliminate as many 'nos' in the environment/around the house as possible.
Choices can also be ones that work for you. My son used to climb onto tables at your son's age. "You may keep your feet on the floor or you may sit in the high chair/stroller" or "You may stay in the yard or you may sit in the stroller" . Containment is a positive option (strapped into stroller or high-chair while we get our work done) so long as you give the child a few items to play with and try not to make it punitive. My son spent a lot of time, sometimes, in the stroller, at that age, but was often given something to do because I needed to cook or open the oven, but it wasn't a bad thing.
For what it's worth, "no" can be an abstract word for some children. I try to use positive direction as much as possible when they are young, telling themn what they CAN do. When we say "Don't jump on the couch" two things are happening. First, the child is focused on the last few words of the phrase "jump on the couch" so you are repeating and reinforcing the idea of "jump on the couch" (because that's the brain of a 16 month old); you are also getting them 'stuck' on that, because they cannot think of a better option on their own. Instead, if you say "The couch is for sitting. Come, you want to jump, let's jump on the floor" you are redirecting a desired action to a suitable place. This is Far more instructive to the child than just saying "no" or spanking is. In this way, the child learns "I can be happy down here on the floor".
Little ones really need help and a lot of patience as they learn to navigate their world. Being consistent in redirecting his attention/actions and moving him in a loving way will make both of you happier and it will teach him *where* he can do the things his little body wants to do. And this all worked very well with my little guy, as well as the children I nannied/cared for. Consistent, friendly and firm. Like I said, too, it's okay to use some restraint when there are safety concerns and to remove problem items. (If I child throws a hard toy, I always remove that toy from the play space after I hand them something appropriate to throw, knowing that they *will* try to throw the more dangerous item again. Don't give it back and expect them to make safe choice. I see parents do this and it drives me nuts!) Be the adult, make the good choices for them... it will help them develop better habits in the long run.
(By the way, I use the term "positive" not to mean "touchy-feely help them feel good about everything" but to mean "here's what you CAN do". )
@Amanda F. -- I think you are on track with my intention. I do not condone bribery for good behavior, food-oriented or otherwise. My intent is to always give two appropriate choices *I* choose to be healthy for kids, not necessarily to modify behavior by mollifying. A co-teacher of mine and I discussed this years ago. We should only offer food as a choice if they are hungry (some acting out is based on hunger), but not use food as a regular distraction. Otherwise we risk creating unhealthy relationships with food or do create kids who expect something 'fun' in order to follow directions. Not good!)