Sail by feel is a critical factor in getting your boat up to speed. To to develop a good sense of feel there are many things you can do to tune up your senses and I have outlined a couple of important ones below.
Of course dress for the conditions but wear light and non-restricting clothes wherever possible. Its tough to sail at your best if you are restricted by bulky heavy gear. Lighter gear also ensures that its easier to feel changes in wind direction and pressure.
If conditions and the type of boat you sail permit, sail without gloves and boots. No gloves allow you to feel subtle changes in sheet pressure. No boots help you to feel up and down pressure better when you are hiking and boat movement underfoot.
Rudder and Tiller
Remove all friction and play from the moving parts of this system. Lubricate pintles and gudgeons plus make sure the tiller extension universal operates freely.
On a boat with a wheel, take any slack out of steering cables but don’t tighten to the point that you restrict movement.
Any friction here will lessen you sense of feel and you will not be able to notice subtle changes in pressure.
Use as small a diameter rope as possible, and this goes for all systems, haliards, spinnaker, jib and mainsheet ropes. With a multi purchase system such as used with the mainsheet, in lighter air remove as many purchases as you are able.
Choose the biggest diameter blocks as you can as this also greatly reduces friction and therefore increases feel.
Avoid cleating sheets and unless conditions dictate otherwise, hold them in your hand. Holding the sheet is the best way to feel what is going on with your sail whether it is the main, jib/genoa or spinnaker. Increases or decreases in pressure are transmitted through your hand and will show you when to make adjustments to improve boat speed.
Sheets need to be user friendly though. Using sheets that are super light but hard on the trimmers hands will be counter productive in the long run. Go for light and thin enough to get a good feel but thick enough so the trimmer will be able to trim for the whole leg.
If you are trimming around a winch, use as few turns as possible so that you can feel the pull of the sail.
Keep hiking straps tight so that you are always exerting upwards pressure on the top of your feet. This gives you a more secure connection with the boat and better transmits what is going on.
Not using footwear will also make hiking under straps give you a better feel for what the boat is telling you.
Consider not wearing rigid hiking pants. In some classes this may not be an option but without them you will feel the boat better.
Onboard chatter and noise
Of course communication between team members is really important but keep it to a minimum. Its much easier to tune into the feel of the boat when things are quiet.
Being able to hear the sound of the water flowing past the hull, wind noises or the sounds from other boats is really helpful when racing.
For a helmsperson, noises other than those created by the boat or others in your fleet hinder their concentration. Poor concentration translates to poor boatspeed.