As training starts to get back going at the high school level, there are umbrella policies and regulations based on your state/district, along with facility set up. As I have gone through the weeks hearing, speaking and aiding in the return to training two things stick out, ratio of coach to player and what to do in the first few weeks.
To ensure your training is appropriate make sure you take things slow. Even though for the last few months many coaches have been very proactive and creative with at home training programs they cannot mimic the stimulus of having coaches and teammates around. Please see protocols from the CSCCa and NSCA who have worked together for these guidelines to help.
Depending on indoor and/or outdoor training make sure you take into account how many athletes you are guiding at once. In the case of group/team training specifically conditioning, it is a important to recognize those athletes with any medical issues (sickle cell, asthma, diabetes, grass allergy, etc). A few great ways to make sure those athletes are taken care of is to have every coach/trainer at the sessions to a have a pocket card (business card size) that labels those athletes with such medical issues, so all personnel are aware. Also, you can have those players wear colored wrist bands, to heighten awareness as well. It would be important to speak and communicate with parents before hand so that they are aware of what is in place. Other important factors to take into account:
Any prescription drugs that athletes may be taking
Hydration: make sure each athlete has enough water and educate them on being hydrates all the time
Cold tubs ready
Education on showering and washing their hands
Make sure all personnel are communicating and working together! Those who work together and understand more time might be needed at this time will be the most successful!