Great tips!
For me, I recently tried the Model Master Liquid Cement for Plastic Models.
It comes in a wedge shaped container with a long metal capillary tube.
Using the technique that T26 recommends, hold the plastic part in place, and touch the tip to the part. This especially is useful when you can get under a part out of site.
Practice the "touch" on something less obvious until you can get used to the flow. You can also use a microbrush or toothpick if you need to guarantee less glue.
A LOT of people in for forums recommend the "touch and flow" system for applications like this, but I personally haven't bought it or tried it yet because my LHS doesn't carry it, but they had the MM cement.
@stik, I know that different glues affect styrene in different ways, so maybe the Tam glue is better, but so far, the MM glue hasn't caused any ill effects on my parts.