Considerations for Selecting a Bottleneck Slide for Guitar
Glass - In my opinion, glass tends to offer the best tone due to it's density. Thick wall quality glass from a wine bottleneck has a desirable heavier weight than the lighter glass found on beer bottles.
Metal - Brass or steel are the most common. Metal has the advantage of not breaking if accidentally dropped. Avoid light weight thin wall slides. They tend to float on the strings, instead of riding correctly and produce a weak tone.
Bone - Serious Mojo factor. Bone tends to be slightly softer / not so bright, but with more of a haunting tone. Mississippi Fred McDowell wore a beef bone ring.
Ceramic/Porcelain - The material varies. Usually lighter in weight, but still dense. They tend to be surprisingly bright.
I prefer a snug fit. Some like it loose and floppy. Knowing my pinky ring size is a 9 (3/4") makes selecting possible options for slides easy by simply measuring the opening for my finger. BTW: Never stick your finger in a bottle. The vacuum will cause your finger to get stuck. LOL
I like the slide to be long enough that it is possible to bar across all the strings. Cigar Box guitars with 3 or 4 strings have fingerboards not as wide as a standard 6 string. A stubby slide may be better.
I would suggest using the pinky or ring. This allows for usage of the other fingers to play notes and bar chords. Although, if you were going to be playing mainly lead guitar while being backed by a band, the middle or index can work too.
Making your own Slide
Search the internet for other instructions. Laying the bottle on it's side, I simply drew a line around the bottleneck where I wanted to cut it. Using a hacksaw, I cut while turning the bottle round and round. After a long time, this created a stress point and the bottle just snapped. Then using crocus cloth, I polished the lip smooth. There are much better easier methods, but this worked for me.
A - Vintage Mateus Wine: Made by me in the 1980s.
B - Keni Lee Model: Made by www.ebay.com Search: willy's slides
C - BonerZ: Made by www.ebay.com Search: bonerz slide
D - Mojobone Works: Made by www.facebook.com Search: Randy Bretz
E - Titanium Bottleneck: Made by Bill Helferich
F - 3/4" Deep Well Socket: Cut down to reduce weight by Bill Helferich
G - Dunlop Rev Willy's: commercially available
H - Vintage Brown Glass Pill Bottle: Flea market find
Instructional Video CDs with email student support
CD 1 - CD 3: Open D and G tuning on 6 string guitar (CD 1, 3 string CBG too)
CD 4 - CD 6: 3 and 4 string Cigar Box guitar
www.ebay.com Search: keni lee