When you are choosing trees make sure they have just one leading branch. A young tree can cope well with two or more leaders but as time goes by they will have problems. The branches will be vulnerable to splitting in windy weather. If you do have a young tree with a couple of main upright branches then one can be cut away. This will allow the remaining branch to go it alone and produce a fine specimen. It’s a good time to look out for the branches now before the leaves come. Don’t worry if the tree looks a bit one-sided for a couple of years after cutting, it will rectify itself soon enough.