Thanks for sending the photo - it looks like your young coral bark maple is going through an awkward stage and it will get a better shape as it matures. Continue to clip off the dark green leaves so it won't revert back to its wild state. You can remove the bottom branches to make it more tree-like but don't take off any more than one third of the branches at any time. Try to follow each branch back to the trunk and remove it entirely rather than just shortening long branches. I have to tell you some bad news. Sometimes when you buy a young coral bark the specimen is not what I would call first quality. Some seedlings don't have very orange bark, some seedlings just want to revert back to green and some seedlings just sprout random branches. This is why when you see a larger coral bark tree for sale at the nursery they are so expensive. The nursery owners select out only the best of the crop. Your bargain tree may never grow up to be as spectacular as the specimens at a nursery but that doesn't mean it can't grow into a lovely small tree - that will always need hand pruning to keep it from reverting.