If you're on a standard DC SFRA flight plan in contact with Potomac TRACON with an assigned code (whether you're getting flight following or not), you stick with the assigned code (both in and out of JYO). Only if you're using the special Leesburg procedures to get in and out of JYO without flying through any part of the DC SFRA other than the Leesburg Maneuvering Area (LMA) do you use the special JYO procedures.
So, going to JYO from CHO, if you're going to fly north outside the west side of the SFRA and then into JYO from the west through the LMA only, you'd follow the LMA ingress procedures:
2. INGRESS PROCEDURES FOR LEESBURG MANEUVERING AREA 1) FILE A DC SFRA FLIGHT PLAN. 2) AIRCRAFT SHALL SQUAWK TRANSPONDER CODE 1227 PRIOR TO ENTERING THE DC SFRA TO INDICATE THE PILOT'S INTENT TO ENTER THE DC SFRA AND LAND AT JYO. 3) BEFORE ENTERING THE DC SFRA, PILOTS SHALL ACTIVATE THE DC SFRA FLIGHT PLAN BY ANNOUNCING THE AIRCRAFT CALL SIGN, AIRCRAFT TYPE AND RUNWAY OF INTENDED LANDING ON THE PUBLISHED CTAF. 4) PILOTS SHALL ENTER THE DC SFRA VIA THE MOST DIRECT LATERAL ROUTE THROUGH THE LEESBURG MANEUVERING AREA. 5) THE DC SFRA FLIGHT PLAN WILL BE CONSIDERED CLOSED WHEN THE AIRCRAFT HAS LANDED AT JYO. 6) PILOTS NEED NOT COMMUNICATE WITH POTOMAC TRACON (PCT) UNLESS OTHERWISE DIRECTED.
...and remember to monitor 121.5 on your #2 while you're doing this.
However, if you're coming from HEF, you're going to have to file a regular DC SFRA flight plan to get out of HEF anyway, so you might as well file a point-to-point within the DC SFRA and see if they'll just take you straight up the west side of KIAD within the SFRA. You also have the option of filing two DC SFRA flight plans -- one from HEF out to the FLUKY gate using normal SFRA procedures, and one into JYO from the west using the LMA procedures.
Likewise, departing JYO for CHO, you'll probably want to head out straight west to clear the SFRA, then turn south to CHO. In that case, you use the LMA egress procedure:
1. EGRESS PROCEDURES FOR LEESBURG MANEUVERING AREA 1) FILE A DC SFRA FLIGHT PLAN. 2) AIRCRAFT SHALL SQUAWK TRANSPONDER CODE 1226 3) PILOTS DEPARTING JYO SHALL ACTIVATE THEIR DC SFRA FLIGHT PLAN BY ANNOUNCING THE AIRCRAFT CALL SIGN, AIRCRAFT TYPE AND INTENDED DEPARTURE RUNWAY ON THE PUBLISHED CTAF PRIOR TO DEPARTURE. 4) PILOTS SHALL EXIT THE DC SFRA VIA THE MOST DIRECT LATERAL ROUTE THROUGH THE LEESBURG MANEUVERING AREA. 5) THE DC SFRA FLIGHT PLAN WILL BE CONSIDERED CLOSED WHEN THE AIRCRAFT HAS EXITED THE DC SFRA. 6) PILOTS NEED NOT COMMUNICATE WITH POTOMAC TRACON (PCT) UNLESS OTHERWISE DIRECTED.
...and again, monitor 121.5 on #2.
Going JYO to HEF, you know you'll need a DC SFRA flight plan to get into HEF, so again, you might as well file a point-to-point and see what happens. This will mean calling Potomac Approach on 126.1 prior to takeoff to get your discrete code, and then calling them on whatever freq they assign after takeoff. Of course, you still have the option of filing one DC SFRA flight plan out of JYO using the LMA procedures to depart to the west, and a second DC SFRA flight plan into HEF from the FLUKY gate and land at HEF using the regular procedures.
As always, make sure you've done the DC SFRA course (or one of its predecessors). If you haven't, go here:
https://www.faasafety.gov/gslac/ALC/course_content.aspx?cID=55&sID=315&preview=true