If you use "orchard prunings" it's not a bad idea to peel as much of the bark off as you can before cutting up into small pieces. Bark can impart some bitterness to the smoke.
I don't bother with "orchard wood" anymore. I just buy the bags of chips in all kinds of flavors. Apple, Oak, Hickory, Pecan, etc. Between Lowes, Home Depot, and Cabela's I usually find what I need and a bag lasts me a long time.
Another great smoke source is "pellets". Just pick your flavor, buy a bag, and get either the Amaz-N smoker maze 12 hours of thin cool smoke and not need to tend the chip tray.
Cabela's has both the maze and smoker tube on the shelf as a rule. Load with pellets, light one end (or both for more smoke over a shorter time) and sit back and relax. Just make a Tent of Foil or flat sheet metal (an opened up piece of stove pipe works) to keep dripping from meat putting out smoldering pellets.
The pellets burn at just the right rate to provide a light "wispy" smoke rather than a heavy "creosote producing" cloud. Use whatever heat source you have to cook but use the pellets for the smoke flavor.