^^^ this is 100% dead on
when I learned the people that taught me harped on the "practice" and "first learn to weld, then learn to make pretty welds"
you can always grind a weld to make it pretty, but you can't make it hold better.
the auto darkening helmets/masks are great, but, if you aren't working in a fairly well lit environment, throw a shop light behind you aimed at what you're welding (or off to the side if that's better in your situation) because without it, you're still flipping your mask up so you can see what you're trying to start on and then flipping your mask down and hoping you didn't move your hand when you did it.
I never thought of the hammer trick, I started off welding steel cattle pens, so to test their strength I just jumped my fat @$$ on them a few times as hard as I could then smacked em with a 5lb hammer in each direction, if it came loose I re-welded it, if not, we called it good. My first big project that I've had to *REALLY* worry about weld quality has been the roof racks I've started making, and those...have turned out rock solid. We beat the welds with hammers, and even turned the rack up side down and slid it under a jeep's tire then dropped the jack out from under the jeep to test the strength of the welds, nothing bent, nothing broke, so, I call it a success. The more you weld, the more you'll learn, and as you learn, you'll get better and better at it.
The most annoying thing is when you have a welder with a very short (read "absofrigginlutely useless") duty cycle...the cheap harbor freight 220V mig welder is 8min on, 30 min off or some crap like that, so, it's great if you need to do little tack jobs, but, apparently you'll burn it out badly if you use it for longer periods of time.