Here's a collection of fairly fundamental sub-topics of playing bottleneck. Some will be obvious to some, others to others. As always, this is just a set of opinions and suggestions and you may find that none of these apply to you.
holding the slide
Obviously, in the case of bottleneck, most people will put the slide on one of the fingers of their fretting hand (generally the left, in the case of a right-handed guitarist). Which finger you use is obviously also personal preference. If the slide you use is very heavy and makes your little finger sore, you might use the ring finger next to it. Most slide guitarists will also fret notes as well as using the slide. Any spare fingers you can find can help -- so many (most?) guitarists will use the little finger for the slide and the rest for fretting.
Chances are that the slide won't snugly fit your finger. In fact, it's probably best that it doesn't. That can make it a little unwieldy at times. So quite often, you'll want to have some of the surrounding fingers crammed up against it to hold it steady as you slide around. Even just that ring finger (assuming the slide is on your pinky) can help to hold things steady. Just be ready to let go to fret some notes and then clamp it back down. Whatever is comfortable, doesn't cause you any injury and can easily be turned on and turned off mid-phrase should suffice.
Part of the art of playing bottleneck involves being able to mute the notes or strings that you don't want to sound. This is exceptionally important when playing in standard tuning, where the harmonic properties tend to lean more towards clashing than not. In any case, you'll find yourself in situations where there's a not being played and there are nearby strings that you don't want to sound.
So how do you mute the notes you don't want to sound?
With whatever you have. Past each elbow and forearm, are a bunch of bones, flesh and digits. If you need to mute something and have something spare and in close proximity, use it.
Muting with your right-hand palm (if you're playing right-handed) is a typical way to mute the lower strings and if you've ever played in a metal band, palm muting will probably be near second nature. If you're playing something with a low part on the bottom strings and a high part on the top few, you can use this to great effect. Muting the lower-pitched strings with your palm will give you a dull thud thud thud, allowing you to yank away at the higher, unimpeded strings and have them ring out with all of the resonance and sustain they have.
That said, a lot of musicians will play and keep the fingers on their left hand (again, if you're playing right-handed) across the strings behind the slide. This seems to be less common if you're playing acoustic blues and seems to lend itself to electric, single-string lead playing, but it's another tool in your arsenal. When you play a note with the slide on the strings, you'll find that the part of the string behind the slide still virates somewhat. Resting your currently-unused fingers over those strings will alter the sound. Whether that makes your sound is up to you.
When I'm playing, I quite often keep my right hand to the one-finger-per-string rule. At least as far as the high three strings are concerned. It's not a case of only using my first finger for the 3rd string etc. If I have a thing I'm playing that uses a few fingers, I'll put my best men forward and they'll generally hang around where the action is at. But any finger that just played a note knows that it's going to have to potentially be called to arms to stop that note while the next finger is fixing to hit its string.