If you are looking to post a picture you basically need to have a link to a web page where the picture is located. Most people (including myself) have a photobucket account (which is easy and free).

As far as advice on your tree its sort of hard to help without knowing how tall the tree is or what species it is as different species have different 'finished' heights. Is the tree planted in a container or is it in the ground? If its in a container it should be top pruned as well as repotted every few years to reduce the root ball allowing the tree to form more small 'feeder roots' and not become 'root bound' where the the root ball basically takes up the whole enclosed area and suffocates itself.

It would be helpful to us, and to you if you would provide a little more info as Mike423 mentioned... But as a general rule of thumb; JM's are very easy to work with, and take well to shaping, and pruning. They can be dynamic growers when you start shaping them; this is something to consider when you start cutting, what I mean by that is if you cut a branch (especially new growth), and if you leave enough room for die back on the branch below the cut it will likely branch out in multiples of 2 or 3 (so depending on how, and where you prune your tree, it can get vey full). However if you want a taller more upright tree simply cut the lowest and most mature branches... I would also suggest one last thing, and I'm sure you may already know this, but You should alway use clean, and very sharp tools for cutting (to prevent possible disease, and to not bruise the Cambium, this will effect the healing time) and never seal the wound with a sealant (to avoid trapping any potential diseases in a perfect incubator).