Don't just lube the exposed part of the AR-15 bolt carrier before shooting, it does nothing. Instead remove it and lightly oil the silver surfaces (where the finish gets rubbed off).
Pipe cleaners are great for cleaning the gas tube of an AR.
A good way to ease into both eyes open shotgun shooting is to put a small piece of tape or a round shot pastey on your shooting glasses to prevent you from seeing the target but learn the feel of keeping both your eyes open.
A roll of masking tape and a roll of electrical tape are great for covering shot holes and extending the life of your targets.
To do a speed reload on an AK, swipe the mag out with your fresh one. A solid push forward on the mag release with the fresh mag will drop it and get it clear with ease.
You can make a great mag coupler by taking an empty dip can with the lid removed and taping your mags to either side of it.