Contact lens fit and assessment related questions,Help is appreciated :)

(1) For the first choice of a contact lens power,
For refractive error of <-4.00,you would choose the same power for the contact lenses.
For >-4.00,you would reduce by 0.25
For >5.50,you would reduce by 0.50
But do make any changes to the power to the astigmatism if the patient has astigmatism?

(2) When checking for tear reservoir quantity and lens movement on the eye,how do you guys estimate the movement/distance/height

(3) Lets say an RGP fit is not good,how do you know when the parameters should be changed,whether is it the power,base curve,diameter or even the whole brand and how much should be changed based on your findings.

(4) What is the criteria of the eye health to fit scl or rgp lenses?(eg. redness less than grade...)

(5) Any tips to fit lenses in first time wearers who cannot hold their blink and squeeze their eyes when you try to insert the contacts?

Thank you