When weather catches you offguard and you don't have time to reef just yet, these are ways to put it off for a moment. They involve using the sails to either spill air or to work against each other to reduce their efficiency.
A Fisherman's Reef is when you ease the mainsheet and sheet in the jib. This will create a bubble in the main that will take away the mains power. This is a very temporary fix that can help to depower the main during a blow. The air that comes off of the jib will blast into the eased main and create a bubble in the luff. This reduces the amount of sail area actually working and sort of accomplishes the goals of reefing temporarily.
Back winding the main is very similar to a Fisherman's Reef, but it doesn't involve easing the main. The over sheeted jib will create a similar bubble to the Fisherman's Reef which will reduce the effective sail area of the main, and depower the sails to a lesser extent than the Fisherman's Reef.
Tightening the topping lift will raise the boom and force a twist into the sail. This will allow you to sheet the sail in close hauled while still maintaining a twist. The twist will spill almost all of the air in the top of the sail which will greatly reduce heeling. The top of the sail can turn into a flag and begin flogging which is damaging to the sailcloth. If the sail begins to flog, a reef should be put in immediately.
Lastly, you can ease the sails and change course onto a run. This will lower the apparent wind speed and make conditions feel somewhat calmer while you put in your reefs.
You may have noticed that all of these alternatives to reefing simply buy some time when you need to reef, but they all end in putting the reef in. This is because there is no replacement for reefing when it is necessary.
Trim, comfort, and control will be restored once the sails are reefed for the appropriate weather conditions.