Like Blueranger: Center the main and forget about it until after you tack.
In dealing with the genoa/jib, self-tailing winches sure help. If you don't have them, it helps if you can use spring cleats to trap the lines, and if you tack slowly, so you can stay ahead of the sail and not fight the winches. As LakeEscape says, a winch handle is not necessary if you can stay ahead of things.
Position and cockpit layout really count with singlehanding. If you can't straddle the tiller, you may want a tiller extension, or one of the various tiller-tamers or the arms that snap into a pocket to hold the tiller over. Holding an exact course during the tack is not important. Avoiding a chinese fire drill and then trimming things back up in an orderly manner is.
It is way too easy to tack too quickly, so use "all due speed" rather than making the fastest possible tack. Once you get into a pattern, you'll speed things up.