It's all down to personal preference whether to do repeat visits or work through the HL. Me, I like to find a WG who ticks my boxes, and stick to her. Well, it's a bit more complicated than that; I work from a 'pool' of three or four who fit my particular requirements, but will very occasionally 'break bad' with someone new. But only after extensive research, mind you, to avoid Romanians and munters...
You will not, IMHO, get the best from a girl on the first visit. If you take the trouble to establish a rapport, it'll make for better subsequent meetings. You also get to know the WG's personality better, which, not every punter cares about; but I do.
That's how I do it...