Note:  some of these techniques, regarding lighting, may not be street legal.  Consult local regulations. Switch to LED tail light; about 10- 15W saved per taillight bulb. Switch to HID headlight.  Expensive, but frees up 20W per headlamp. Do not use a rheostat (variable resistor), series or dropping resistor to control your heated clothing to less than full power.  These units waste most of the extra power.  use a bimetallic strip thermostat, or better, a switching electronic thermostat.   These units are much more efficient. On systems with dual headlights that each have both hi/lo beam, disconnect one of the bulbs.  55W saved.

LED brake lights and turn signals help too, but they are not as important because they aren't on for long.  Additionally, most LED turn-signals don't save any power at all, since they are designed to draw the same as an incandescent bulb, because mechanical flashers depend on a certain amount of current through the bulbs to flash.  You can now buy electronic flasher units at auto parts stores.  Get the kind that accepts a variable number of lights.  This means they do not depend on a certain current to work properly.  This kind of flasher works with LED signal lights that do not have a shunt resistor, allowing you to save that power.

Clean and tighten connections to the main fuse, regulator, rectifier, generator/alternator, battery, ignition key switch.  Coat with dielectric grease.  This eliminates power losses in the charging system. Run at higher revs in town.  Not graceful, but gets the job done in a pinch. Get a heavy-duty stator.  There are manufacturers that make specially-wound stators for higher capacity.  You will need to buy a heavier regulator and rectifier, as well.