You probably know that pleasant feeling when, faced with a broken laptop, a crashed website, a lame operating system, you approached the old man and said: Leave it to me, I'll solve the problem.. You did it for free, for a relative, a friend, a pretty girl or a colleague. After that you received other desperate calls, because "you are the coolest". You solved the problem every time, because you are a hero and you saw a challenge worthy of a craftsman like you.
Well, you were wrong every time. Here's why it's not a good idea to offer your services without getting paid:
When you start solving a seemingly simple problem, you are actually signing a social contract. The owner of the broken computer entrusts it to you as if it were his child. You fix the problem, but the next day you get a call: something else broke and it's most likely "your fault." The owner expects a guarantee even when you've given him your time and skills for free. That's why it's good to get paid when you fix something.
Tips, upgrades, concert tickets. They're not valued at their true value if they don't cost anything. Free tips are rarely wanted. Free upgrades "were included anyway." Ticketless access? The band isn't exactly a big deal, anyway. People associate the value of a service with the amount they pay. If it's expensive, they naturally assume it's worth the money. And most of the time it is.
If you fixed it once for free, what does it cost you to fix it again the same way? It was free last time, why does it cost now? That's why it's good to set expectations from the beginning: time and skill cost money. In fact, that's the difference between professionals and amateurs. The former are paid for what they do.
From a system upgrade, you end up with a virus scan, and then a broken hard drive. You've created the image of a savior hero and you'll always be called upon, including for 30-minute discussions where you might be contradicted.
Your time costs money, as does the knowledge you've gained through years of school and work. So does gas and any consumables like blank DVDs or any other materials used in the repair. You pay.
If you work for free, if you give gifts left and right, it will be harder for you to ask for money. Your credibility will decrease because the client will assume that if you didn't ask for money, you didn't know what you were doing or you made mistakes. Get over the embarrassment, ask for your money openly and politely. Your clients will see this as a sign of self-confidence.
(Clarification: never ask your wife or mother for money)