When I want to glue to surfaces togther then I am advised to
roughen the surfaces first.

In this particular case I have two fairly soft hard plastics
(about as soft as styrene but not as soft as polyethylene) which i
wish to stick together.

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I have a choice of adhesive:
(1) "super glue" - cyanoacrylate adhesive
(2) Bostik or UHU - general purpose adhesive
(3) Evostik - contact adhesive
(4) Araldite - epoxy resin
(5) hot melt adhesive from glue gun - various formulations

The cyanoacrylate super glues should be good for this application
but too often I have tended to get disappointing results from
this type of glue. I find the hot melts too can be problematic.

So I will probably use either (a) a Bostik/UHU type of general
purpose adhesive or (b) a contact adhesive.

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The QUESTION is what sort of roughening is best to allow this sort
of glue to bond strongly with each plastic surface. Each surface
is currently smooth.

(ONE) Should the roughening be quite fine. Perhaps similar to
using 300 grit glasspaper?

(TWO) Or should the roughening be almost visibly "streaky" as one
might get using 40 grit glasspaper?

(THREE) Would you change your recommendation if I made a different
choice of adhesive fro the range above?

Thank you.