Support straps on Vents and Drains

How often should drains be supported with straps? Do vents/vertical runs need support? I have been using the plastic hanger straps because the metal ones destroy my hands. I have been connecting one screw on either end should I be using more than one screw?

P.S. - Thanks to everyone's help on this forum, I will be testing my drains and vents over the weekend for my rough plumbing inspection on Monday. I have my fingers crossed.

Does anyone have any advice on the straps?

UPC tables list the support requirements for pipe.
ABS requires rigid support every four feet horizinatlly either 2x4 with v-notch and plastic plumbers tape or UPC listed hangers. Loose plastic NO. Nor metal stra - it fails to resist upward thrust and can cut the piping.

Cast iron requires support within 18 inches from each end.