never do anything your good at for free
honestly.
I find working in any IT area a rather boring job(for me, i like working with my hands far too much), i'm an experienced(or was) computer forensic and was self-employed doing pc repair when i was in college because i got sick of people asking me to fix their computers for free because i knew what i was doing so i started charging for it and kept myself pretty well floated during college with more free time than my mates. You wouldnt expect a mechanic to work for free so why should anyone with a different skill do the same? at the end of the day if you can do something many others cant, dont work for free and thats all self-employment is.
Getting your foot in the door can either be easy or very difficult and i would say working part or full time to start with, doing something other than the line of work you wish to set yourself up in business doing while doing some freelance work in your free time is the best way to start. It's hard work but if you work it pays off after a few years, maybe even sooner if your lucky
not doing the same things job/self-employment wise is an important one i learned, 1. you have a competition conflict between yourself and your employer and 2. if you've been coding for 8 hours straight you hardly want to go home and do the same damn thing for someone else.
And i dont know anyone who got their foot in any door by doing something for nothing, mostly they just couldnt cope with a workload they weren't being compensated for.