I can honestly say I've had people ask about the ways they may be able to support the site. I have a few different ways:
Paypal: There is a link at the top of the main page. I do not know if they will let you hide your name, but all I use that for is to properly address you when I thank you. Paypal is also how I process read-ahead service when I produce a new serial, and a reader wants to read it all at once rather than wait for it to post week by week. The stories will always be free, I just give those that choose to the ability to read it first or ahead of the regular posting schedule.
Patreon: Also posted to the main page. I don't know if they let you hide who you are, but again I don't use it for anything. Currently the best thing you can get from me through Patreon is reading SS stories as soon as I have them ready. Typically the post a week or two later on the site. Again, all work will post for free eventually.
Amazon Wish List: This is a new thing. I think all you need is an email. Basically I made a list of things I like, but that I likely wouldn't buy for myself. If you see something, it's another option. You can access it here.
I don't really have other methods - maintaining a PO Box for a check or money order would be entirely counterproductive from a cost standpoint. I understand that adding a credit card to something, where someone may see it on your bill is an issue. I just don't have a solid way to address it.