IMO all eventers should do a Lucinda Green clinic - at least once. Highly recommend her!
She teaches riders to be brave - to focus on line, balance, engine, accuracy, and staying out of the horse’s way. There is no “counting strides” permitted.
She sets up progressive questions – starting on day one with footwork exercises (lots of skinny jumps set on an angle, and accuracy questions) then x-country is the second day - building on the skills from day one.
The tough exercises she has riders do are set at lower than competition height, making it easier for the horse to read and respond without being and feeling overfaced.
She is very enthusiastic when you do things right, but does not suffer fools gladly; you really have to listen to her!
I have a student doing Novice (and hoping to move up to T this year) who would really benefit and I’ve been nagging her for the last couple of years to put this on her “to do list” for 2025. She already accomplished her other bucket list item last year which was doing the Waredaca 3-Day at N - which was a fantastic experience for her and her horse. 
I told her I would be sure to “prep” her, having ridden in three clinics with Lucinda on two different horses (mother and daughter) at three different levels.
My student started out in Hunterland, but has become a strong, balanced, tactful and bold rider over the past three years because I insist on “mastering the basics” before moving up; I think she will rock a Lucinda clinic, will love it, and will get a lot out of it – as will her horse! 
She still finds the prospect a little intimidating! 