There is no 'easy' way into this... but for the persistent coach, the doors will open. Several approaches come to mind
1) USAG has a magazine called. "Technique". It's available online & is for the advanced coach. Read those articles carefully.
2) USAG also offers 'conferences' & occasionally those conferences will provide learning opportunities like you are searching for.
3) See if you can get on 'staff' for an advanced camp or clinic... being able to interact with more advanced coaches will provide an environment that's RIPE for learning. Often, to get on staff, you'll need to take a group of students with you to attend the camp.
4) Some of the gymnastics magazines offer training videos for sale in the back/catalog section, by mail order... you'll just have to subscribe & experiment.
5) When I coach camps/clinics in the gym I have sessions set aside to coach the coaching staff. I usually have them assist me with spotting groups so that they get a chance to practice what they've learned. I've found that the surest way to provide an environment where the kids will continue to progress AFTER I've left is to help the coaches develop better habits of coaching.
6) Lastly... if you can get hold of a student who's already accomplished the skill that you're wanting to teach, take her aside and practice spotting that skill with her. Just make a commitment that you will MASTER one advanced skill... and dedicate yourself to it.... schedule time each week. Once you've got the basics down with one student who's already got the skill... pick up a few others who almost have it...and refine yourself to a more expert level.
Have fun, be safe, push hard!
Coach Wayne was the Head Coach for the Savannah College of Art and Design Cheerleading team and Executive Coach of Olympic Gymnast Zuzana Sekerova. His articles, videos, and books have been used by students and instructors worldwide since 1991. Coach Wayne is available for tumbling instructor certification training. For booking information, coaches/owners should text or call 912.238.1747.