Practice self rescue techniques every now and then.  It is surprising how many class IV boaters don't know how to self rescue these days.  Many also lack aggressive swimming skills as well.  They are a danger to themselves and others.  When swimming with a boat and paddle, hang on to both in one hand and drag to swim while swimming with the rest of your body.  It is important to stay upstream of the boat, the last thing you need is to get caught between a swamped boat and a rock.  Set an appropriate ferry angle to make it easier to get to shore.  If you are quickly approaching a strainer, push off the boat and swim away from the danger.  When close to shore, toss the paddle like a javelin onto shore.  You can also push the boat quickly in easier water and swim to catch up.  This can be faster than towing.  Here is an video that demonstrates the technique: Self Rescue.

Body Positions

In general, we try to stay with our boat and paddle.  Not only will they be needed post-rescue, a boat is an enormous flotation device.  Defensive swimming, feet on the surface and downstream is beneficial for energy conservation.  Even while resting, scan dopwnstream for opportunities to reach a stable location like the shore or a midstream eddy.  Once you have acquired a safe target, use aggresive swimming techniques to forcefully charge into the eddy.  Aggressive swimming is essentially making the same moves you would do in a boat.  Thisd often requires ferrying and catching eddies (i.e. heads first).  If other boaters are around, listen to their directions as they can see much more than you.  When dropping over ledges or going into holes, ball up to help with floatation and most importantly avoid foot entrapment.  Look for breaks in strong hydraulics and work your body to those escape locations.  Sometimes diving is necessary to catch the jet stream of water underneath large hydraulic backwashes. 

Handling Equipment

Where possible, we try to hang on to our equipment.  Stay upstream of the boat to avoid getting caught between a boat full of heavy water and a boulder - ouch!  It's generally best to keep the boat upside down as it will hold far less water and provide more bouyancy.  When approaching a strainer, a boat full of water can be used as a launch pad.  It's not as weffective as a rock but sometimes a couple of feet trajectory is enough to avoid the entrapment.  Paddles (with practice) can be used to provide more propulsion than hands alone.  This is a fun exercise you can practice in flatwater until you get the cadence mastered. 

Often the fastest way to get a boat to shore is the bulldozer method.  Hooking the tip of your boat in the cockpit provides additional control and speeds the recover process.  With more than one boater, someone can grab the downstream end with their hand and quickly push.  This gets the boat into shore even faster.  Setting a ferry angle helps to balance the forces and get the boat across faster.  Often the fastest way to get a boat across a stream or into a safe eddy is towing with a rescue vest and tow tether.  Make certain you know how to use the quick release feature.  The tow tether is the most reliable way to run a rapid with a swamped boat as well.  This can be necessary to avoid having the boat get pinned.  Here is a video that cover this subject: Capsized Boat Techniques II.

Canoe paddles are a breeze, kayak paddles are very awkward.  If you lack a tow tether, stack both paddles together and paddle.  This technique is slow but does work.  When you get close enough to shore, toss like a javelin.  I find it much easier to hook the paddle shaft with my tow tether and drag the paddle across.  Canoe paddles can be stuffed in the top of your PFD (in milder water).  If you have a raft or canoe, you can carry inside the boat or tie to the craft.  Don't dilly-dally on paddle rescues.  Paddles are often dark in color and blend in well with water.  They can be very difficult to find when lost.  When rescuing as a team, put the strongest boaters with the swimmer, then the boat.  You can usually assign a single paddler to deal with the paddle.