Some of this depends on the specific design but I do a lot of single-handing and have done some single-handed racing. The first thing in my book is to be able to make all adjustments and reefs from the cockpit. It is important to mark halyards and reeflines so that you can make rough adjustments on the fly. I also have my spin sheets marked so that they can be preset for jibes. I prefer two line reefing since it is very reliable,quick and lets you play the luff and outhaul separately which reduces the frequency of reefing and un-reefing. I prefer a tiller over a wheel since a tiller extension allows you to move around the cockpit and make adjustments and still have the helm in reach. I prefer a twin foil headstay since it permits quick headsail changes. I don''t like roller-furling for singlehanding. Roller fuling is fine when it works but when it jambs you are in serious trouble if you are single-handed. My other gripe for roller furling for single-handed racing is that a partially rolled sail has lousy shape. Change to high grade roller bearing blocks. Friction just plain wears you out. Rig up a comfortable place to sleep in the cockpit where you can catnap safely and still keep an eye on things. Install high quality jacklines and points to attach your harness. Practice sailing single-hand until everything is second nature. Pre-pack meals so you don''t have to leave the deck as long. Add a smaller cooler in the cockpit for cool drinks. I find that it is very easy to become dehydrated when you are single-handing as your time sense becomes a bit distorted. Make notes as there is no-one else there to remind you of things. Put together a mini-nav station that you can keep in your lap. (Mine is a plastic clip board in a plastic envelope, a small protractor, a pencil and a bunch of 3x5 cards that I use instead of dividers.) Look around and appreciate what a gift it is to be able to spend quality time with only yourself and the beauty of the world we sail through.
I just want to add one thing. Take your time to do things. To be in a rush is your worst enemy. You cannot affort to make mistakes that can hurt you badly or fall of you rboat because you didn''t clip your harnas correctly. Think before you move and what you will do in which order. And as Jeff indicates all boathandling should be second nature.