Re: Lessons learned: Do not practice casting in the backyard
I won't claim to be qualified but.............. When you cast a fly line with no leader attached you may be guilty of a bit of cracking the whi; this will fray or split a vinyl line at the tip.
As for wind knots in an Amnesia butt section........ You may need to shorten the practice casts a good deal and become proficient at control using a short line before going for any great distance in casting. We all want to cast long when just starting out but doing so just causes problems.
Although there are some people who will pick up casting very quickly, for many becoming really good at this will take a long time. I don't remember practicing casting on grass although I do sometimes test a new rod this way just to feel the action. There is nothing that will compare to water for practice.