Re: Derek Roddy here!
I use that hand foot exercise in 4 combos...
Do these 4 combos at various tempos. Within your comfort and push tempo out of your comfort level and come back.
Doing these with a time limit....say 10 minutes each...will make sure you can comfortably get through the entire 10 minutes at your comfort tempo. When pushing....don't be concerned about cleanliness, etc you focus on that when you come back to your comfort level.