It depends on when u made an appointment to make ur first visit.
I went to the boutiques during weekdays afternoon and I was lucky cause the stores are mostly empty, hence I was able I spend more time talking to the consultants and trying on 3-4 gowns (I even got to try on 5 cause the consultant were so enthusiastic talking about their dresses. But they weren't pushy).
If u go during their busy times likes weekends, they might 'rush' through the service with u.
Some boutiques and their consultants are nice enough to let u try more than 3. But 3 is usually enough for them (and u) to see which designs and colours suit u.
They won't let u try a lot cause they also know u might still be going elsewhere to eye shop first.
Only until u confirm and signed with them, that's where u would spend hours choosing ur gowns for pre wed and/or AD