Limb it up and remove trunks as you wish. Don't cut the top.
Remove branches entirely to another limb but don't cut the branch in half. This thread posted below has a lot of info.

A shorter bushier crepe can be had in several ways: Cut to the ground. It will rebound (don't worry!) and for several years be smallish. Or cut it in half every year -this is crepe murder and generally despised among anyone with any sense because it ruins the form of potentially beautiful trees.(however, I have one plant, a Hopi , that I do this to each year) Or, cut it down, kill it will round up and plant a small variety.
Crepe myrtles are not all the same. Some only get 5' high others get 30'. Some are rounded in form, others are columnar. They DO NOT HAVE to be pruned to bloom well.
Anyway, I hope you have fun pruning. I love pruning my crepe myrtles! I have a dozen different varieties and love this plant!

Here is a link that might be useful: Crpe Myrtle Time Southern Gardening Forum

I, for one, hope you won't commit crape murder. There is a lot you can do to tidy up your tree without whacking it to smithereens. Cut out all the dead stuff - goes without saying. Then stand back and see what else needs to go to make a nice shape. Cut out all the suckers - they are bad about that. And that should pretty much do it.

I only wish my poor dry crape myrtle sprouts would grow up to the point where they might need some pruning!

I am trying very hard to NOT commit the crape crime.

The dead branches do go without saying, I was wanting to get additonal tips on the inside pruning of still living branches that cross over each other and the suckers too! I take it I can just cut them anywhere and take them out, I have read varying reports of exact placement of cuts and misc. so that the tree has the opportunity to create that great shape we all want.

I do have a lot of suckers that grew out of roots earlier this year, and they bloomed along with the parent tree. These blooms are only a few feet tall! I thought to myself I could cut them off and somehow plant them elsewhere but each time I tried the pieces died back easily within a day or two.

BEEZ- thank you for the link, it did answer a few small questions I had about pruning in general

Lyle in Concord

I am not sure of the exact protocol for rooting CM suckers, but I think you need a bit of root or a 'heel' - a tag-end of bark/branch/root left where you pulled/cut the piece off the base. Dip the end of that in some rooting powder (or not, but it can make it easier) and the stick it down into a hole (made with a pencil or such) in damp, very well-draining potting mix, press the hole closed around the base, put a plastic bag loosely over the whole thing and leave it in a shady spot for a few days. Water if it seems dry, gently, and remove the bag for a while if it seems too wet. After about 2 weeks, the bag can go altogether. It can take up to 6 weeks to get any root growth, so be patient. Oh yeah, you want to take the cutting from a semi-hard shoot that isn't flowering, about 4-6" long, cut off leaves up to the top 2, and cut them in half, so there is little that needs to grow/be green while new roots grow. I would take several cuttings, because, most likely, about half won't strike for you.

In general for removing suckers, if they are coming from the trunk, it's easiest to rub them off as soon as you see them. If you have not, and they are only a few inches long, then also rub them off, and if they are very tall - the usual time for me, I have to admit - then try to break them off at the base. If you cut them, you will get multiple sprouts from the cut surface, but if that is what you can do, do it.

If the suckers are from roots, the same applies, but see if you can dig down and break them off, since they are, if possible, even more prone to make multiple sprouts from cut surfaces! It's a LOT easier to rub off/cut a clearly seen sucker, and it dulls your clippers less (if you are cutting them).

If branches cross, then look to see which one does the most for the over-all shape of the tree, and take the other, back to the trunk or to its origin. If it's a large branch that needs to come off, then make the first cut a couple of inches deep, or less than halfway through, at the bottom of the branch, a few inches out from the trunk, then cut the branch off , cutting from the top, beyond that, leaving a stub. Last of all, cut the stub off. This will prevent the weight of the branch from breaking it off before you finish and stripping off a section of bark.

Hope this is helpful information, and not confusing.

DIBBIT- thank you for all of your useful information. I am going to try to prune this tree the best I can perhaps this fall.

Lyle

Lyle..trust me..you could cut it to the ground and have the stump ground to 8" below ground level and the determined crape would grow back.
Happened to me. For two years I thought it was well and truly gone and I planted things in its place. The third year it reappeared. When they do, it's bushy..not at all tall and attractive growth.

So, as others have suggested..work with it, trim out the dead and crossing branches. You might even want to root prune it as is done the year before moving a mature tree. Leaving it in place,root pruned will force new root growth. Then a year or two later the crape will be invigorated and bloom properly. You might even try underplanting it with blooming shrubs after that root pruning. It could turn out to be a very satisfying project.

Don't necessarily think a stick is dead. I moved a 4' crepe in late May with very little rootball. I had to heavily stake it.
The following weeks we had high nineties and the thing lost all its leaves and was brown. Until last week. With the recent showers it has sprouted leaves all over.
I knew it wasn't dead because it was green underneath and would eventually recover. I only watered a few times too.

I also found a smaller crape myrtle along the side of my house. I thought at first it was a dogwood until I saw the small purple bloom in only three spots in the entire tree. This tree is spindly and severely twisted/gnarled, it looks great but the growth is very very sparse, partly due to the huge pin oak that is growing ten feet from it. It sucks the water up and shades it quite a bit. I may take it down and let it grow back again straight instead of 9 foot long branchs that hover 3 feet above the ground, if possible.

Lyle