Original helmet build up?

I have only built a couple of Stormtrooper helmets, the first I joined the faceplate to the dome tightly, and didn't really like it, the next build I left a small gap between the two parts.
Is there a preferred way to join these,just enough to add the rubber trim? I have seen various buildups, what do you experienced guys do? Thanks.

It's generally recommended that you have the brow trim attached the cap&back when you do the test fitting and positioning.

Yep as Mathias rightly said i always have the brow trim in place while fitting the back and cap to the facplate. Otherwise you may have problems with final fitting as you have found out.

Thanks guys, I looked at the originals sitting built up outside AA's shop without the trim, some looked tightly fitted and others looked pretty sloppy with gaps between the lid and faceplate. The difference is not great , just wanted some other folks views.

I've had several fan made lids with a bit of a gap on one side of the brow and have never let it bother me so don't worry if any builds you make do have a slight gap.

The only thing is sometimes the rubber trim has a tendancy to fall off while wearing the helmet.