I would imagine you may get different advice on this from different people. What I do kind of depends on the kit, the plane and the medium the kit is built from. For plastic injection kits I use mostly Plastic cement because it doesn't set as quick so if needs be the top wing can be moved. If I am doing a plane with a large number of struts like some of the two-seaters or bombers I may use white glue incase one or two struts pop out (you don't want the plastic cement on the end of the strut to go against the underside of the upper wing). I might follow up with superglue when they are all in place. In almost all cases I have used monofilament (fishing line) to rig the plane, this has the added bonus of fixing the wing properly in place and hugely strengthening it. I also use a jig I knock up out of cardboard to align and keep in place the wings. For resin kits I would use a tiny, tiny amount of epoxy resin then rig it. It is also entirely possible to attach the two wings without glue if the struts fit neatly in their location holes provided it is rigged.
Hope this helps, what are you building?
