required vs. optional tag w/ many different forms

I've read many online resources about this issue, but I think this situation is a little different. I'm working on a large app with lots of different forms. I've read in most places that using the (optional) tag is the best way to indicate that a field is optional. However, in this app, there are several forms, each of which vary drastically in the number of required vs. optional fields.

One form may have up to 20 optional fields, another may have 90% required fields. Some are split ~50/50. I still like using (optional), but do you guys have any suggestions? I'm a little split just because some forms have no optional labels while some other forms have the optional tag on every single form label. Thanks