Some really good advice here...I paddle alone most the time, although occasionally I will have a partner. I go out for long periods of time in very isolated areas. When you are out there alone and the waves and wind start acting up you do have to constantly ask youself if you are doing everything correctly...there will be no-one to get you out of a tricky situation; except yourself.
Buy the best equipment you can afford...listen to the weather reports constantly...check all charts. You must believe in yourself and your abilities. When paddling alone you must err on the side of caution! Do your homework.
THOSE THAT FAIL TO PLAN, PLAN TO FAIL!