Does anyone have any tips or guidance for studying and training for the EIB tests?

SMCT

Ft Benning publishes, updates, and revises EIB criteria. Local testers are given SOME latitude with specific tasks, but there is pretty clear guidance on how to do such EIB. I believe it is open to public (or at least open to CAC holders).

Things that will DEFINITELY be on EIB: Weapon qual, PT test, day and night land nav, 9-line MEDEVAC, evaluate a casualty, 12 mile ruck.
It has been FOREVER since I gor my EIB (or even since I was an 11B) so these things SHOULD be there, but I cannot guarantee: Call for fire, operate a radio, treat a casualty (user's choice of injury), camouflage self and equipment, ID and employ grenades.

There will probably be more. Prior to testing, they should have trainingwhere they ID each task and thoroughly familiarize with TCS, including go/no-go criteria. (For us it was 1 week of "practice", 1 week of testing.)

Approach each station like you've never performed that task before. Listen carefully to how the graders want it done then do it that way and that way ONLY. Forget how it may have been done at your last unit, how you were taught to do it by Sgt So and so, etc. Do it how they want it done

It’s muscle memory. Go through the tasks at a comfortable pace over and over. If you’re trying to beat the clock and overthinking it you will probably choke( like I did).
Try trial runs without pressure.

I would be cautious about getting too far into preparing for EIB material. If you learn bad habits or incorrect information before you go, it will likely resurface when you are under stress on test days. Prep for the things that aren't mandatory for you to perform in a step-by-step process - APFT/ACFT, weapons qualification, etc. Familiarize yourself with weapons, if you aren't already. Other than that, just wait for them to teach you the way THEY want you to do it (this may not be the optimal or most up-to-date method), because that is going to be your grading criteria.

They wouldn't let me take it in the 80's as I was a 19D... the only problem now is the influx of youngsters wearing the CIB... and most consider the EIB as pretend...

Your supposed to have a few days practice runs I thought, then the actual for the record day. During my time in I just used the skill level manual published for the Infantry MOS after I saw what stations they had setup.