I NEVER cleat the main upwind and in fact the cleat is deliberately angled so it's impossible. Coming in off the wire I use a combination of pulling the sheet up to my shoulder and allowing the sheet to ease slightly as the boat passes through the wind - bear in mind that I don't come in until the boat is almost head to wind because I began the tack while still on the wire. The combination of easing the sheet by my movement and being mid-tack allows the boat to pay off slightly on the new tack and it's then a simple matter of straight back out on the wire on the new tack and sheet in while adjusting course.
Downwind I WILL cleat the main but because of the angle of the cleat it's very easy to blow the main if I have to - the downside is that I have to come back into the boat to re-cleat it if that's what I want! Gybing is straight forward as you've only the spin sheet to worry about - similar to a tack, commence the gybe and come in easing sheet as you go. Take the sheet with you to the opposite side of the boat, hook on and get out and sheet in as you go. Be very careful to only gybe through enough angle to actually gybe - too much of an angle and the cleated main will have you over!
Practice, practice, practice!