I spent nearly a year spanning 2023-2024 commuting from KROA into the DC area, using mostly KHEF and KIAD, but occasionally others--KJYO, KGAI, KBWI, and even KCGS, which is inside the "no-fly zone" FRZ.
If you're going around, but not into, the DC area, plan on heading northbound up the east side of the SFRA and southbound down the west side. There are ways to "cheat" and go opposite the flow (to avoid weather, mountains at night, whatever)--my typical one between the NYC area and KCHO was to file KRIC as my destination and KCHO my alternate, which always got me east-side routing, even southbound, and then once I was mostly past DC, I'd ask to "divert" to my alternate. Expect your altitude to be constrained passing south of the SFRA for KDCA traffic and on the west side for KIAD's. The through routes around the SFRA are busy airspace but IMO not crazily so.
Note that even if you're going by (and not into) the DC area, if you're flying VFR within 60nm of the DCA VOR, 91.161 requires you take special training. See https://www.ecfr.gov/current/title-14/chapter-I/subchapter-F/part-91/subpart-B/subject-group-ECFR4d5279ba676bedc/section-91.161. Sites like AOPA and faasafety.gov can steer you to the training.
If you're going into the DC area, bring your A game. Take all the training you can find for the SFRA. (I have a FRZ PIN to go inside the "no-fly zone" to places like KCGS, and that's training and vetting beyond all the rest.) I mostly use KHEF there but have used KIAD ($$) a bunch, too, and it's fun to mix it up with the big iron there--you just fly really fast! (Note: KIAD almost feels cheap, fees-wise, compared to KBWI!) Under no circumstances do I ever fly in/out of the SFRA VFR--I'm an IFR-only guy there.
I've been flying around DC's airspace since the mid-90s and so am pretty used to it. (9/11 messed it up considerably.) Happy to try to answer any specific questions...
--Up.