There are a few different kinds of finger and thumb picks. Most are made of plastic but you can also get metal picks, which are a little easier to bend into the right size for your fingers. If the plastic ones are too tight or loose, you can heat them up a bit in hot water to reshape them to fit properly. They should be tight enough to stay on, but not so tight as to cause pain or cut off circulation.
Many players just use a thumb pick and don't bother with the finger picks. Below is an image of a typical finger and thumb pick. The finger pick is worn as it appears in the image, with the picking surface under the fingertip.
The little finger, aka pinkie, is not often used in fingerstyle or fingerpicking, mainly because it's too short. However, if yours is long enough, by all means use it. Mine is, but I find it very difficult to control, so I stopped trying to incorporate it into my playing years ago. It seems to have a mind of its own.
Notation and tab often indicate which picking fingers you should use with the letters:
T = Thumb
I = Index finger
M = Middle finger
A = Ring finger
My favorite way of playing guitar is to use my bare fingers rather than a flat pick. I have always had trouble controlling plectrums (plectra?) ... they would either swivel around between my thumb and forefinger, or I'd drop them (usually inside the guitar) or I'd lose them all and have to use bits of cardboard or pieces of plastic as picks. I eventually decided to forget about them altogether and just use my fingers. I did experiment with finger picks and a thumb pick, but once again, if you lose or break one, you find yourself up the creek. I have grown to love being in direct contact with the strings, but many finger stylists do use thumb pick. It all comes down to personal taste and comfort.
Fingerstyle and fingerpicking are not quite the same. Fingerstyle I guess does include fingerpicking, but the latter is more pattern oriented and is really a fancy and rhythmical way of playing arpeggios, whereas fingerstyle is a way of orchestrating the guitar ... playing bass lines, melody lines and chord fragments at the same time, weaving them all together into one 'part'. Fingerstyle, to my mind, maximizes the potential of the guitar. Not many instruments allow you to do this and to simply strum or play single note lines seems a waste. I have put together over 80 fingerstyle lesson arrangements over the last few years, of all levels of difficulty, so you'll have plenty to work on if you
As I mentioned above, Fingerpicking is pattern-focused, in fact it's sometimes called 'pattern picking'. There are, of course, countless patterns, but all follow the same basic rules: The thumb handles the bass notes within the pattern and the index, middle and (sometimes) ring fingers handle the treble notes. This general rule applies to fingerstyle as well. The way the hand falls over the strings makes this the most logical and comfortable way of plucking the strings, and if you bend your right wrist positionwrist down slightly (see image) you'll find it even easier to get a nice clean pluck. The more perpendicular to the strings your fingers are, the better. You don't want to be dragging your finger tips across the strings during the pluck; you'll hear that as a scraping noise.
I have always let my fingernails grow out a bit on the picking hand. I keep them just long enough to be seen peeking over the fingertip if you look at the finger tips from the palm side. That little bit of nail just brings out the high frequencies a little more, but I know many players who just use the fleshy tips of their fingers and nothing else. I also let my right hand thumb nail grow out a bit and it also makes for a brighter sound on the bass strings. You can also use finger picks and a thumb pick if you prefer. They give you more volume and keep your fingertips from getting sore, but they can feel cumbersome and make it more difficult to control the dynamics as subtly as when using bare fingers. As always, experiment ... the only way to really know what suits you best is to try them all out.
Fingerstyle, as the name implies, is more of a style of playing the guitar, a way of playing. Most players start out using flat picks, probably because strumming through chords is the easiest way to begin making music, and flat picks are good for that. But the design of the guitar allows for much more complex playing than just strumming through chords, and to do that you need to use more fingers. Some players keep their flat pick and use the two remaining fingers (middle and ring) to add notes on the higher (thinner) strings. This is called hybrid picking and is a very useful technique to learn because you wind up with the best of both worlds ... you can strum, flat pick your way through single note melody lines and also grab chord fragments and arpeggiate higher notes with the free fingers.
The main aim when playing finger style is to orchestrate the piece of music, meaning that you merge bass lines, melody lines and chords into one part. All classical guitar is fingerstyle and is played on nylon string guitars, but over the last few decades, many great players have adapted fingerstyle to steel string and even electric guitar and popularized the technique. James Taylor is probably the best known on steel string, Mark Knoppfler on electric. The style takes a while to come to grips with as there are no set patterns to learn, but the more you play, the easier it becomes to do. You will find that certain keys and chord shapes predetermine what you can or can't do, and after a while it becomes second nature. But, the basic rule that the thumb handles the lows and the fingers handle the highs applies throughout.