Same advice as above:
- I make nuptial encouragement suites out of an overlapping bedroom of two beds with two double tile food stockpiles (with barrels!) one for booze and one for roasts. Once the stockpiles are stocked (with one empty barrel and one being filled) the two subjects are goaded into their bedrooms using a burrow for just the two of them and set up a tavern zone associated to the general tavern over the room. Once they FINALLY get inside I disable the tavern and wait for everyone else to leave, after which I lock the door and enable the tavern again. This gets them socializing, which is great for, well, socializing, and eventually marriage (assuming they're compatible). They may have to be let out if they run out of booze or food. Once the marriage announcement appears, I remove the tavern zone and wait, using DFHackery to check when the female falls pregnant, which happens after the two have spent time in adjacent tiles and then one of them moved, but not every time. If you're not using DFHack I'd probably just leave them to their own devices for two weeks or so to make reasonably sure they've consummated their marriage. Sleeping beside each other does not result in pregnancy as far as I've seen, but I think I've observed a case where the female got impregnated while the male was asleep, but not the reverse.
- Once the dorfs aren't doing their duty to proliferate properly, it's time to draw them back into their (now common) bedroom by adding them to the burrow (unfortunately there's no way to enable/disable burrows with dorfs still assigned to them currently) and pull them back into the burrow, with the same hassles as the first time. I use a tavern zone to give them another reason to go to their room beyond eat/drink/sleep, but once they're safely in there (they can escape, which is annoying), and everyone else have been kicked out the tavern zone is disabled so they don't have anything to do but to eat/drink/sleep/procreate, which typically doesn't take long. Kicking others out probably isn't necessary, nor is locking the doors (apart from the escape stupidity), but, well, modern sensibilities consider it rude to have others present when procreational activities are ongoing (which isn't reflected either in the game, nor, to some extent, historical practices).
Note that this is based on 0.47.04 and earlier, but I don't think this logic has changed beyond dorfs having become a little better at getting hitched on their own. However, I haven't heard any indication that they're more active at procreating ("better", assuming you want more dwarflets, rather than consider them to be a nuisance).