dont expect anything, go with the flow, dont try to accomplish goals more ambitious than make out and feel good.
a small amount of viagra (depends on how much anti-erection drug you take, your age and fitness etc.) will make it possible to get an erection with stimulation and it will go down after ejaculation (which may be much more difficult on drugs so DONT expect it to happen), enjoy the sex for what it is, and dont stress about reaching climax.
i suggest making out massaging teasing feathers gloves blankets etc. et al DURING the come on and peak and rushiness etc, and work on intercourse with an attempt to climax (dont kill yrself trying to cum) on the cruise/come-down, and if its too hard jsut chill for a couple hours and try again. it sux when you exhaust yrself to the point of discomfot and pain jsut trying to cum.
i sugegst taking the viagra (25-50mg at the most depending on yr situation as i mentioned earlier) a half hour or hour after the drugs, the timing is just good, and its easier on yr liver which is filtering these chemicals in yr blood.
i like to dissolve in the mouth (the stuff im taking atm is a little rough on the stomach) partly also because i like the SLIGHTLY accellerated effects, but not the full blown omgness of snorting, but it is nice to snort a little more later (depending what yr taking of course)
head is amazing, but dont get selfish, and its easier to do than it sounds...even if both of you are eing and if you are 'taking turns' (one of you Es at a time) the non-dosed party gets bored and that can be awkward too (one night my gf and I ed and she got pretty queesy and i was virtually left to myself, kinda sucked so be prepared for that possibility too)
my favourite thing to do is take it and jump in the shower with your girl, give each other a nice sensual wash and the feeling of it coming on in the shower, then getting out of the shower with it in full swing is quite fun.
enjoy, dont stress about anything going wrong or not being perfect, you may both get distracted a lot but it doesnt matter if you both have fun and a nice time, cuddle during comedown (we get REALLY quiet) have your up and down pot, eing at home with a girl is fabulous.
one more thing, watermelon