Well I have a simple slab reefing system that goes like this: One line is involved, it is tied off at the reefing clew cringle. It passes the normal clew cringle, then the normal tack cringle, then the reefing tack cringle, and is kept in place with a big figure of 8 knot. When you reef, you lower the sail to the proper position, grab the figure of 8 knot, and pull. It helps for the other person to hold the boom up and you should end up with a reefed main. All that’s left is to cleat up the reefing line to a cleat on the mast, and tie up the sail ties. I also have a sail tie on the reefing clew cringle to tie the sail down to the boom and hold it’s weight, which I tie up once the main reefing is done. I must say a picture would tell a thousand words on this one!