And you learn by doing it right AND screwing up.
In the end, it's nice to be able to stand back, look at a project and say YOU DID IT. Of course, it doesn't hurt that you saved a whole bunch of nickles in the process, and may even have done a better job than a pro would have done.
I just finished painting our house. That involved:
(1) Scraping spots where the paint was raising.
(2) Sanding everything (I have toys and used a sander that lets me switch between angle grinder (aggressive) mode and polish (random orbit). I used some high end disks and they worked so well I only had to use three. The vacuum attachment grabbed so much of the dust I could have worked in my Sunday best.
(3) I primed all the raw wood spots.
(4) I used foam backer and caulk to take care of every crack, crevice and so on that would have detracted from and compromised the end job quality.
SIDE NOTE: You can use a 1" chip brush with bristles cut down to around 1-1/4" long to apply caulk. Where your finger would leave a smooth spot the eye would be drawn to, on textured surfaces, the brush follows the texture, and also pushes the caulk into the crevices and holes.
(5) I back-brushed and back-rolled the paint I applied via my airless. I could have just used the 5 gallon bucket by rolling the roller across the surface, lifting it out a bit, then using the sides of the bucket to spin it more to knock off excess.
SIDE NOTE: Back-brushing and back-rolling make a visible difference in the end appearance, AND it pushes the paint into the holes and crevices (accounting for that notable difference in appearance from just spraying).
Then there was the deck railing that wrapped three sides of the house, and stair rails. All of which needed the scraping and sanding.
When all was done, we had about $1,000.00 into materials. It was a lot of work, but it felt good knowing having done all the above done by paid types would have cost nearly $10k.