If you're semi-comfortable with public speaking, see about talking to a Rotary club (or similar) about the new tax law. You have to be careful, as a lot of clubs like this do not respond well to advertising one's business, but they appreciate informative talks which get your name out there. It's a form of soft marketing.
If you're looking for a harder marketing, my first thought is a postcard mailer. I've been told that postcards are more likely to be read in between the mailbox and the trash bin, and that unsolicited letters don't get read because it's too much effort to open an envelope (frankly, I can attest to that). But I really don't know how effective that sort of marketing is, especially if you're looking for a higher tier clientele.