I have read many times how people complain that they find it difficult to sail through the wind when switching from one tack to the other when sailing upwind, especially when you don't have a jib sail to assist. I had the same problem, and so I just paddled through the wind to assist. But this means a bit more work unclipping the paddle, making a few strokes and then stowing it again.
But after reading some sailing tips online I learned a great technique that makes it easy and quick every time.
When you are making your tack, first try to get as much forward momentum as possible, even if it means reaching a little wider than you would like to initially. Then when you do tack, don't overdo the rudder, going full rudder to try to make a quick tack can slow you down because the rudder in full 'lock' also acts as a brake.
Then when you do tack, if you find you can't sail through the wind, wait until your sail 'luffs' (flaps around in the wind), then if you can manually take hold of the leech of the sail (the bottom corner closest to you), push it into the wind on the winward side of where you want to tack to force the sail to catch the wind. You will find that when you do, the wind will pull you around onto the tack you want, and you will begin to make headway, then you can trim the sail for the heading you want.
Works for me every time, but it's easiest with a sail that has a boom you can reach.
Water lapping against the hull, warm gentle breeze, fish straining on the line... how much sick leave do I have?
Mulloway 1.2m (x2)
KG Whiting 45cm
Skipjack tuna 58cm