When it comes to finding a slide that fits, start with advice about what makes a slide work: material, weight, finger fit, length, color... wait, color? At RBGS we know that the color of a boro slide is rarely (if ever? never?) discussed as a slide property when choosing a slide. We think it should be. The weight of a color boro slide depends on it's color! Bet you didn't know that :^) It's not obvious because it seems kinda confusing: the heaviest (weight) slides are the lightest (color)! That's right, the heaviest are the lightest. Pink and black slides of identical length and wall thickness might weigh 35 grams (pink) and 30 grams (black) respectively. So, in addition to the bling factor, the colors chosen for same size slides should be considered: since slide weight does make a difference in tone quality.
Here's a list of links to articles that talk about what makes a good slide, then links to a great little lesson (or two) from a fellow who really understands the 'slide technique'- and demonstrates it nicely for beginners- and finally a search link for 'Guitar Slide Interest Groups' on Facebook. Joining a group or two can help you quickly get your balance, with advice and recommendations from other folks who've walked the same path you're on.
Note- the practice part is entirely up to you.
A bit of good advice on slide selection:
Article in Guitar World - by William Baeck - How A Slide Taught Me To Make Up My Mind
Scott Ainslee, Teaching Artist and Performer - On Choosing a Slide For Slide guitar
A couple of terrific starter lessons for beginners:
Matt Smith Killer Slide Lesson #1
Matt Smith Killer Slide Lesson #2
and if you liked his first two lessons, here's a link to all eight Matt Smith Slide Lessons:
And this is a search link for Facebook Guitar Slide Interest Groups.
And please, let us know if we can help you with a custom boro slide! In color! Creativity rules...