My husband (I don't tell him this, of course, it would be a terrible blow to his notoriously fragile male ego) has a rather...small penis. It measures about five inches erect. So with me the problem hasn't been deepthroating, it's been how to create enough pleasure all along the amount of shaft I do have to get him to cum.
I usually start with a good ball-licking. I can suck both his balls into my mouth at the same time, and he loves it when I roll the testicles inside his sac with my tongue while holding the whole thing inside my mouth. When I let them go the next thing i do is lick his anus (he always washes with soap and water before we have sex, by the way) and then his perineum, the tender skin from his anus all the way to his balls. Once I have him moaning from that, I lick in a straight line all the way from his anus to the frenulum (the sensitive skin just behind and under the head). I'll use just the tip of my tongue for a light sensation, then use the broad flat of my tongue to almost push his balls up into his body. The contrast between feather-light touches and firm swipes gets him going. It's also a really good way to get his precum out (for some reason I don't mind the taste of precum, although I don't like swallowing regular cum).
Then I take the tip of my tongue and swirl it around the head of his cock, which can be tricky sometimes, if I set myself some kind of no-hands rule before we start. Hubby is completely vanilla, and has no idea why I would want my hands cuffed behind me when I'm giving him a BJ, but he's willing to go with it as long as it means he gets to cum. Most of the time I don't bother with the cuffs, I just tell myself 'no hands' and that works for me. Mental handcuffs, so to speak.
Annyway, I pull my lips down to cover my teeth and then take the head of his cock between my lips like that. Then I swirl my tongue around the head of his cock, again using both the tip and the broad side to alternate the pressure and feel. Tastebuds are more concentrated around the tip, so the tip feels better, with more bumps for friction. Then, and only then, do I take his cock in my mouth.
I wrap my upper lips and the corners of my lips around his cock; I keep my tongue extended down the length of his shaft, and press my lip to the underside of my tongue, with my teeth still tucked inside my lip to keep from nicking him by accident. I've even, once, placed a wad of gum against my back teeth on either side and up and down, to keep him from feeling them when I take him in. He hates feeling the hardness of my back teeth on his head. He hates feeling anything hard against Mr. Happy period.
Once I've done that, I start moving my head up and down his shaft, while simultaneously flicking my tongue in and out of my mouth. The flat upper side of my tongue swipes the underside of his shaft, and when I withdraw, and because his cock is filling my mouth, my tongue kinda has to curl up to fit in there, and the tip brushes up against his frenulum again. I'll do this in a straight up-and-down motion for a few strokes, then, the third or fourth time, I'll turn my head a little to the left or right (ten o'clock or two o'clock) as I go up, then turn the other way as I go back up. The side-to side motion does a lot for his end of the sensation, though I have to be careful and keep my eyes closed, because I get disoriented if they're open and I turn my head without having my glasses on to focus my vision. In fact my eyes are usually closed for the whole thing. Sex too; glasses get fogged up when we're going at it, and i found it easier to just take them off and keep my eyes closed. Most of the time he's looking through his Penthouse magazines while we do this, so he doesn't really notice whether my eyes are open or not.
I'll retract my tongue into my mouth and curl the edges of my tongue up to cradle his cock, and do this in an up and down motion for a while, then I'll wrap my lips around his cock and suck on him like a lollipop. I have to be careful not to suck too hard; the intense pulling gave him an ache once and he asked me not to suck so hard. Usually at this stage the magazine goes down and his eyes close, and he comes after that.
I give him a blowjob twice a week, full blowjobs. The rest of the time, I start by giving him a blowjob and finish up riding him. This is mostly because with his small size, my pussy doesn't clamp as tightly on Mr. Happy as she used to before I had two babies. As he puts it, I'm all stretched out now, and it doesn't feel the same. I've suggested he try it in my butt, but he hasn't been receptive to the idea, and I won't make him try something he's not willing to do.
I don't know if all of this helps anybody out there...