I was said to start with 25mgs when in HRT, and if that's not sufficient, up the dose by another 25mgs (and so on). Nowadays i mostly divide a 100mg tab in 4x25mg pieces, and if needed, take 2 x 25mgs within half an hour between each dose. This way i experience zero side-effects. 50mgs can also work well, but only if you've taken it the day(s) before, otherwise you'll most likely experience side-effects. When taking the full dose, i.e. 100mgs, you'll inevitably experience them of which some are not just 'bad' but also (very!) painful (especially the crushing headache, whereas the red face makes you 'just' look like Hellboy for up to an hour whilst the vision impairment is 'just' annoying). All of those are listed as side-effects in the instruction leaflet btw.
I've just began trying out the combination with ~5gs of L-Arginine, but can't say something useful for now, but it's said to be worth a try because you should need less sildenafil.
So it's essential to start low and stagger the dose if needed (which is mostly the case, because 25mgs won't do much from what i've heard and experienced by myself)!
