Here's my outline- first, the basic procedures.
Trim up: A day or two before you use your pump the first time, it's a good idea to clip pubic hairs at the base of the shaft of your penis then shave (very carefully) with a safety razor a narrow ring around your shaft and about half way down your testicle sac if you are hairy there. Doing this ahead of time will give any tiny nicks time to heal before pumping. The clipping/shaving will provide a clean surface for obtaining a pressure seal with your cylinder rim. In my experience, a few hairs can ruin a good seal. This will not change your pubic appearance much, and a bonus is that it will give the illusion of your being longer before you've even pumped once. When you start itching during the day, it's probably time to shave again.
Prepare Your Cylinder: Have ready: an indelible ink felt pen and a clean, dry wash cloth. Connect the male and female couplers of your cylinder and air tube. Spread a thin layer of lubricant on the bottom rim (or flange) of the cylinder. Apply and spread a small amount of a good, glycerine based lubricant around the bottom, inside, two or three inches up into the cylinder.
Apply a thin layer of the lubricant to the glans of your penis and to the shaft, but not all the way down to your testicles. A slippery testicle sac skin makes it easier to suck one of your testicles into the cylinder under pressure. This is not the end of the world, but it doesn't feel good when it happens. I don't like the sensation at all and it means I have to re-establish a seal before I can continue.
It's easiest to get an initial seal if you go into the tube erect or semi-erect. You can also pump up if you are flaccid. If flaccid, increase pressure very gradually as you achieve an erection under pressure. Hurrying is not good for your vascular system and penile tissue is very sensitive. When you have a normal erection, you don't achieve that in a mere 20 seconds. Take your time, work up slowly.
Wipe your hands dry with the wash cloth. Sticky hands make supporting the cylinder or manipulating the handles of a hand pump a slippery problem.
Place your penis in the cylinder. With your free hand pull your testicle sack down a bit to accommodate the cylinder rim. Fit the bottom rim snugly against your pubic bone and twist the cylinder a quarter rotation, then back, to create a firm seal. You are ready to pump.
I think timing is very important in pumping. As you begin to pump and know that you have an adequate seal, check your watch and begin your timing.
Pumping feels different from anything else I'd experienced. When I did it the first time I was not prepared for the sensations; it all got out of control before I could release the pressure, and I ejaculated into the tube. Semen under pressure has nowhere to go but everywhere within the tube and I was sure for a few seconds that I had blown myself up. Not so; but I learned quickly that I'd have to take a more distant and scientific attitude. I haven't had that problem since.
The first thing to learn is to understand the difference between pleasure and pain. The line can be very thin. Do not go beyond pleasure to pain, ever, because pain brings tiny skin hemorrhages, major and nasty blood blisters, and flesh distortions. If you bruise or blister, you will have to quit pumping altogether until you heal. There should be a firm sensation of pulling and a pleasant sensation of expansion of your shaft and glans.
Toward the end of your first session, take your felt pen and mark the outside of the tube with a line indicating the top-most point the that very tip of your glans has reached inside. You will use this as a marker to indicate your gradual progress during further pumping sessions.
For beginning pumpers especially, when your session time is up- QUIT, no matter how much you like what's going on in the tube, or how good it might feel to you. You are stretching your skin and the tissue of your penis in ways they have never been stretched before. Do not get carried away with that. Just stop and look forward to the next session.
Each time I finish a session, I add some lubricant to my penis and spend a couple of minutes doing massage of the entire shaft and glans, paying attention to all surfaces. Massage has the effect of evening out any blips you may have created by being over-enthusiastic with your pressure or timing and assures complete blood flow, and blood exchange within the penis. Massage will NOT make abrasions or blisters go away if you've overdone pressure, though it may help some in the healing.