TJ. Thin glue capillary or wicking. This is for, for instance, attaching pieces of PE  to plastic. Place the piece on the plastic & drag the thin glue around the edges.

I use a tattoo needle which has a long snout. I lightly load the whole snout & lay the snout level with the PE & pull along the joint.

On rounded parts good practice to tack at points makes it easier. Then complete.

Just thought are we talking plastic cement or c/a superglue ? I use thin C/A for the above.

For sticking plastic larger pieces I use Tamiya Extra thin cement or Mr Hobby MrCement S.

The S is very thin & I use for small pieces.. Tamiya for Fuselages etc.

For both cements you only need just enough to soften goohy the edges being attached.

Just run the brush in the cement tops along once of perhaps twice keeping to the joint.

Always keep a "model making" (they are harder than the babies type) cotton wool bud to quickly wipe excess before it begins to work on the plastic.

Plastic gloves. Better for me without as your fingers can feel

Laurie