Oh, yes, carrots, I've been trying to think of an incentive/reward system. Toddler's friend has balls in a jar for positive behaviors. But Toddler's friend is a lot more tantrumy that Toddler and has regular time outs, etc. Toddler's not wired that way (or maybe we're more laid back and don't come down as hard) and usually we tell him not to do something once and he stops. Not all of the time but we follow through with whatever consequence we've told him would happen (for example, "No throwing trains, Toddler, that's not a nice thing to do." Train gets thrown again, "Toddler, I told you not to throw your train, if you throw again I'm going to take your train." Train gets thrown again, train gets taken, "Toddler, you threw your train after I said not to so the train is mine for two minutes." Sometimes he sulks about it but usually not because he realizes he's not going to get it back immediately. When it's given back he doesn't throw.
I'm more inclined to do a ball in a jar (or something similar) because he could put the object in, help count, etc. I just need to find a jar (I can use pompoms that I have) and work out the best way to explain it to him.
As MrScout says, Toddler's usually very good at sticking to things he's agreed to such as "Toddler, we're going to go into the shop and get the groceries THEN we can go to the Tractor (those ride on things outside of the shops that TS doesn't realize move but he likes to see them). Is that okay/Do you understand?" Then there's no whinging for the tractors before we go into the store but at the checkout he will ask "Tractor now?" And even "Remember, two episodes then it's time for bed. This is the first episode. Okay, this is the second episode, no more after this one." And when that episode is done he'll get up and go for the stairs. But for this, even though he says he'll stay in bed the temptation to get out is too great.
I'm not horrible to him, but I don't make eye contact (that's hard) and I just lay him back down and pull up the covers.