RESEARCH is so important when choosing a consultant. The first thing I want to caution you to do is find a consultant or consultants who can do your install AND your retightenings. I write this because some consultants only do new installs. Also I chose to get my install in a different city than where I lived. So if you opt to do this, you will need to consider who to do your installs in advance.
I would NOT go to a consultant who has NO References. I chose my consultants based on client referrals. Interview their clients. Make sure you see and examine their work with your own eyes and hands.
Make sure the Sisterlocks Consultant is using the Sisterlocks Tool.
Examine the Sisterlock Consultant's work including the grid, parting size, and size of locks.
Chat with them about the size of Sisterlocks you want, the maintenance, the products, etc.
Make sure they do a tester lock, provide you with a Sisterlocks starter kit, provide info, and get your info to the Sisterlocks Home Office so that you can get a certificate with your Sisterlocks birthday. This may not be important to you, but I wanted a record of who did my locks and when it was done.
My awesome consultant in Boston, Jacqueline Myers of www.hairstoyounaturally.com also gave me a calendar, info about the locking stages, and so many tips on how to maintain the Sisterlocks she installed. She provided braiding and banding info as well as the bands to do it and the technique on how and when to wash.