Man reading directions always helps and attention to detail.
1. I bought the two corny keg thing from Midwest. I got it in a thd everything and tefloned one conneciton that didnt have anything. I saw two nylon rings tie wrapped to the relief pin. I was like hmm those must be spares without reading the directions. Turns out I had a slow leak out of the nut wear the nylon ring should have been that thds to the c02 bottle. I found it with soap spray. I wasted a whole bottle on one keg as it is empty now right at 2 weeks. The directions that came with it clearly stated to put in in. Woops. I thought it was talking a super long time to get any carbonations.
2. The first keg I filled was done without cleaning the keg. Yeah. I assumed it was cleaned from midwest. I looked in and it looked ok, but should have cleaned like I do everything in brewing I dont know why I skipped it this time. I didnt know it was anything to worry about till I tasted my beer and it had a big time off flavor to it. I thought it might have been in the brew until I opened the second keg and turned it upside down after opening it and a salty looked fluid poured out. I smelled it and sure enough it was the culprit to the off smell/taste.
Oh well at least I did them both on the first batch. Hoefully I wont have to many more mistakes. I love learning the hard way!