Lightly trim the branches that are most out of shape.

Take care not to shear too much off of the plant, ... as the most brightly (fall) colored leaves will be those from the outer layer of leaves ... and shearing off that layer of leaves ... will make for a very unattractive shrub come fall.

The best recommendation I've seen for more extensive re-sizing is to trim the bush before it leafs out in the spring.

Check out the link below for more info on Burning Bush

Here is a link that might be useful: Truth About Burning Bush

If you've been shearing, and want a natural shape, start pruning it with thinning cuts instead of heading back.

Here's a link to info about the effects of shearing.
http://www.plantamnesty.org/shearmadness.htm

Below is a link to a website with pruning information. Scroll down for how to make thinning cuts or rejuvenate a shrub.

Here is a link that might be useful: link

This is a highly invasive shrub where I live. I'd suggest getting rid of it and trying something else - perhaps boxwood.

How big will a dwarf burning bush get? I know I will have to prune but on ave. compared with a regular burning bush?

It's hard to snip at the tops of these and get an attractive result. Better to cut the whole thing down low to short stumps, early in the year and start it over from the bottom.

July, I've learned a lot in the past 2 years. "Dwarf" burning bushes will eventually grow 4 to 5 feet. It is very hard to prune them and still retain a natural shape. Shearing is out of the question... there is nothing natural about it! Instead, if there is a broken, diseased or dead branch, cut it deep into the shrub, back to the trunk.
Memmet, my euonymous is a well-behaved little specimen that has not spread or seeded.

dads neighbor had one on the driveway .. that had a 5 inch diameter trunk .. for the first foot out of the ground ... it was at least 12 feet high ... and was reaching 8 feet to dads driveway ...

with permission.. he cut it about 6 inches off the ground ... and it regenerated itself within one year [i dont mean to full size .. just to a nice size] .. since there was no insult to the root system ...

and after that.. he took better care to prune it annually .. rather than rely on the neighbor ...

cut it down as noted above.. and it will be fine.. and if it dies.. even better... but it wont ...

ken

Ken, Your dad's bush is definitely a different variety. Sometimes the species are just uncontollable, so you must choose varieties carefully. I've had my dwarf variety for years and it is still only 3 feet tall. In fact, it has been such a slow grower that it has been a source of frustration. I only needed to prune it because of a few dead tips.

More than one dwarf/compact form on the market, eastern nurseries continuing to select and introduce these (and new Norway maples, Japanese barberries etc.) despite the weediness of these back there.

Long-established 'Compactus' I have cut down to stubs twice in Island County, WA and had come back to nearly previous size within a few years.

bboy, a lot depends on location! Here in Canada zone 5, we have a hard time keeping things alive... buddleia for example, yet the same plant is an invasive nuisance in Seattle. (I have gardened in both.) Burning bush is not a problem here, but Manitoba maples definitely are!

I'm in Alberta, Canada, Zone 2. I planted my dwarf burning bushes last spring and they are all leafing out right now due to an early and warm spring. Mind you, we also had a very mild winter, I don't think it got down below -25C.