Basically, my strategy is to cut the back and sides a short length, usually a 3. I do the top with a 4 or 6 in the summer, and an 8 (1 inch) in the fall or winter. Then, I use the #4 guard to blend the two lengths. This will (hopefully) make more sense in the video below!
When using waterproof hair clippers, it is generally best to cut with the hair dry. If th hair is too sweaty/dirty/oily it tends to stick together, and does not cut evenly. For this reason, we can't cut hair outside in the summer – the boys are sweaty within 2 minutes!!
If you simply cut with the trimmer clipper and stop there, the haircut will still look a little "home done." Touching up the ears, sideburns, and neck with scissors and a trimmer really help! Use scissors to trim any long hairs over the ears.
Then use the trimmer to cut a straight line on the "sideburns." Looks much better! I also use the quality hair clippers to trim the hairline along the neck.