I wouldn't recommend anyone in the UK trys just painting outside, for the simple reason at ground level it would get ruined on your adverage day.
Painting isn't difficult to achieve good results at the best of times providing you have a reasonable idea of what you need to do, but if you was to paint outside in the slightest of breezes, you'd soon find you'd got alot of bits in your paint you didn't bargain for.
Your far better in a garage if possible for spraying, spraying in basments isn't ideal in the least due to little ventilation.
If you can spray in a garage, hang your work from the roof at suitable points, then spray it, or if you have some type of table, ie paste tables are great, get one of those, get a useless can of spray and give the table a blast with it, this will help stick all particles to the table so they don't end up on your work, you wouldn't believe how easy it is for this to happen.
If your in a garage a number one tip i can recommend is, get a watering can or hose and dampen all the floor in the garage where possible, this will help stick all dust and simillar down to the ground so it won't end up in your work.
You'd be supprised every other little thing makes a big difference, those are some of my personally tips, and ive got a good reputation for my paint work. Then again i do have alot of experience with spraying in general, ive painted a good few bits on cars aswell at various times on custom stuff, aswell as body work repairs, ive not had anyone go away un-happy with my work yet