Previously we have been out at, with my impressions of each. Haven't been out in 2021 so I don't know how busy they are this year.
Cedar Ridge Preserve (near Cedar Hill State Park)
7171 Mountain Creek Pkwy, Dallas, TX 75249
Very busy with lots of trail runners and hikers, narrow paths with shade, limited parking, hilly for medium to tough workout
Murrell Park (north side of Lake Grapevine)
880 Simmons Rd, Flower Mound, TX 75022
Busy but not overwhelmed by mountain bikes and hikers. narrow paths with some shade, small ridges for medium workout
Wynnwood Park (east short of Lake Lewisville)
1000 Lebanon Rd, The Colony, TX 75056
Relatively lightly used by bikes and walkers, wide improved trail with some shade, essentially flat so easy workout.
I am investigating the Trinity Trail on the west side of Lake Lavon. It is maintained by the horse organization but it open to hikers too. I was just looking for something more isolated but still relatively near the metroplex.
http://www.trinitytrailriders.org/trail-map/