Practicing on a pillow is an easy to find, quiet practice tool, that many drummers overlook. Tapping on a practice pad might be quieter than your full kit, but it can still be enough to drive your neighbors nuts. If you live in an apartment, or it is late at night, or you have another sort of “noise-sensitive” situation, wife/girlfriend/baby is sleeping, find a good pillow and some sticks. I usually use drum corps style sticks to help develop more strength and endurance, but any stick will do. Set up a click or some good tunes to chop along to. Anything with a strong rhythm will suffice. I usually start with basic warm-ups and increase in complexity as my arms, hands, fingers, and mind start to loosen up.
What is great about the pillow exercise is the lack of bounce back, forcing you to work a bit harder than you might on the kit. You will have to acclimate physically to the differences. You will need to control not only the down/ in stroke, but also the up/ out stroke. By saying down/ in, I mean playing literally IN to the drum. Think of your favorite hard rock or punk drummers. The up/ out refers to the rebound stroke. Many players pull the sound OUT of the drum. Perhaps more finesse with less power for example. Think of your favorite be-bop drummers. These are obviously fairly blunt and over generalized concepts and comparisons. Good drummers will be able to balance their own power vs. finesse given the musical situation.
You will notice that you might fatigue much quicker than normally. This is because you are working harder and developing strength. Try single strokes with both L and R hand leads. Double strokes with both L and R leads. Mixed single and double strokes.
Remember the key is to take it slow and develop your skill over time. Trying to push too hard too fast is a common mistake. Tension will only limit your ability. It will work against the ‘Flow’ that you are trying to create. Even slow singles will work you out more than you might think.