At first I have them on a very long training leash and practice their recall over and over and over (with treats). I run around in the different directions and ask them to come to me, then treat and praise every time they do.
If you make your calls high-pitched and exciting and ask them to chase you, then crouch down to welcome them, there is very little chance they won’t follow. Most dogs love that stuff!
Then when I’m confident in their “stickiness,” I drop the training leash but let it drag behind them so I can step on it if needed. Worst case scenario, if they get away from me too fast DESPITE my vigilance, I can yell at someone else in the park to step on it, which is easy because it’s so long.