I find its easier to blend with for me when Im going to a longer than 1/2" length on top, straight hair anyways. Once you get the hang of it it works good. A combination is good, if Im going from a 1 on the sides to fingerlength or more on top I usually blend into the top with my comb then use the smallest guard to take the 1 line out. I prefer the Oster flattop comb (I think thats what its called) for this.
Also I use shear over comb to take out dark spots at the end of my cut. I like to use the small taper combs for this.