My technique is to clamp hard to a table. A clamp on both pieces that will be connected. I also at times need to use a version of the quick claims as Glenn shows above in the link but I find that the pocket screw - regardless of the accuracy of my joinery - invariably wants to pull the two pieces very slightly out of alignment. I don't want to do extra sanding either so I use glue and clamp so that my two pieces simply can't move by the force of the angled screw.
To the philosophical question raised about M&T or pocket screws, I can't justify the added time to use M&T joints on plywood cabinets. I will for solid wood pieces but not your basic vanity or kitchen cab. Just my 2¢.
"... for when we become in heart completely poor, we at once are the treasurers & disbursers of enormous riches."
WQJudge