Oh, I give assistance to people in identifying problems with their gas equipment here all the time, and will gladly coach people in doing repairs themselves if I think it's safe for them to do them. If I think a repair is unwise for a DIYer to do, I tell them that too. That may be the best advice and help I can give a DIYer!
Thermocouples are replaced a lot more often than they are bad. People usually replace thermocouples when the pilot burner wont stay lit, bexcause it's an easy task to do, the part is cheap and fairly readily available. However, it's far more common for a dirty pilot orifice to be causing the problem than the thermocouple.
So when such a problem is reported, I'll typically try to help diagnose the problem accurately, which usually doesn't involve replacing the thermocouple. But if that is the likely problem, then I'd encourage people to replace it, for the reasons given above.
But the MAINTENANCE would involve cleaning the pilot orifice. Do that each year, or even each two or three years, and you will largely avoid the issues of pilot outages or pilots that are hard to get to stay lit.
Those are my biases in offering advice. However, other people on this board offer advice too, and they may have different methods that they use in doing so. And sometimes I'll violate my own rules when there seem to be good reasons for doing so.