Decreasing sleeves

When it is time to decrease the cap of a sleeve, what is the best methodology. My pattern just says “decrease” but does not suggest how.

Thank you so much for your help.

Gretchen

I assume the cap is currently being worked flat?
I would do matching decreases (ssk, k2tog), assuming you are “knitting” on that row, at the start and end of the row. If you were purling then do p2tog and SSP.
http://www.knittinghelp.com/videos/decreases

If your sleeve is in the round you would do the same matching decreases but on either side of the round marker (which corresponds to the start and the end of the row).