How should I start making custom PCs?

[Chris]

I dont think the other dude had the right answer.what you want to know is how to advertise about what you do.You should start with family and close friends and suggest them to tell their friends too.
Flyers even though old school are a big help,post them everywhere large amount of people gather.
like cleaners and you can also try to advertise at a local radio station.hope this helps.