I shoot primarily with DSLRs, and an assortment of lenses ranging from wide angle to telephoto. I also own a couple of point and shoot cameras, which I use when kayaking or when the bulk of a DSLR and lenses is inconvenient. (These point & shoot cameras, while limited in what they can do, are very easy to use, convenient to carry, and take very good pictures.) (Their biggest failing, in my opinion, is that they are not great for photographing tall buildings, as they tend to distort the lines. (Known as Parallax))
Tip # 1 - When I first started photographing butterflies, I was convinced that a telephoto lens (70 - 300 mm in my case, ) was the best lens choice. I shot butterfly images with this lens on several occasions, and soon realized that a lower percentage of the images than I had hoped, were usable. A relatively high percentage were blurry or out of focus.
I then decided to try my 100 mm macro lens, which gave me a better ratio of usable to non-usable images.
Tip # 2 - Even though I had managed to increase my usable image ratio by going to a macro lens, I was still shooting a somewhat low percentage of usable images, so I started trying to find ways to get better success.
I decided to switch from shooting in auto mode, to shooting in fully manual mode, which allowed me to set my shutter speed and aperture as needed.
I also decided to shoot at shutter speeds of 1/250 - 1/500 of a second, depending on what the light was like, and what type of butterfly I was trying to capture. (This was an important move in getting my usable image ratio up.)