Hello boss we are not able to understand ur question plz be clear
The answer is it depends upon the design rules which we get by the foundry and those are minimum width,minimum distance between poly to poly and so on... these are the design rules.It doesn't mean that u shud always use meet the design rules i mean there may be a situation that u will not be able to go with a design rules so at that time u can keep 0.08 if the design rule is 0.07
I hope it is clear now
Bye take care