All of the above suggestions are excellent. I will add one more peice of advice that has helped me throughout the last 32 years since I took my first metalshop class. It was standard practice in class to test your welds.
Weld on scrap steel of similar thickness and joint design to the welds that you are going to be constructing your part out of, then test it to destruction. This is part of the same procedure that will be used for the various AWS welders certifications that a guy must obtain to be employed at any number of fabrication jobs.
Here are some pics of some TIG welds that I made when I had practiced enough to actually start to use. I used the same steel and joint design as I was going to construct my part from, tried a couple of different weave patterns, then put it in my 55 ton shop press to try to break it... :evil:
As you can see, the part remained intact, distorting the weld as if it was a single peice of steel. The angle those parts were welded together on was twice what you see there. The round depression is from the press ram.
It took 11 tons to bend and distort that peice of steel like that.
Here is the part I was building..Shockwave crossmember for a 68 Imperial with a 9" ford and 4 bar setup.
You should also make welds on scrap, cut the sample apart at right angles to the weld, then use some of the spot check materials commercially available to check for voids or no penetration at the weld bead to base metal. You can also get friendly with the local machine shop, and have the part magnafluxed.
You can also weld your samples, then put them in a vise, and beat the part apart, or bend the part right at the weld...If the weld breaks, you have not succeeded in welding it.
I hadn't stick welded in years, so when I wanted to use my stick feature on my TIG, I did some sample parts..
Welded one edge in a T joint on 1/4" mild steel.
Start bend.
Point of failure.
As the steel had bent considerably past it's yield point prior to failure just past the weld, I considered this weld a success.
Every new joint design goes through the same process at my shop. Especially if it a production part, several samples of the actual part get tested.
I sleep well at night, I do not worry about my welds at all.
One more thing....practice..practice and more practice.
There is no substitute for seat time.
Later, mikey