This is for axeric. I'm just learning gas welding. The only tip I can give you is practice, practice, practice. And the correct tip for the thickness of metal you are welding. I have a Victor#2 and a #0. The #2 I used for the rocker pedal was a tad small. I should of used a #3. So I had to get a hotter flame than I really wanted to use for the 3/16" pedal. But it all worked out.
This video is practical for filling holes in sheetmetal. The guy is really laid back. Sounds like a surfer dude. LOL.
The following video's are good too for the 3 different types of flames. The guy in the video has a nice calm soothing voice for teaching. But he might put you to sleep. LOL
And here's a chart for the possible tips.
I hope this helps.