One of the things I recommend practicing with your dog as often as possible is Come when Called. Building up a reliable recall with your dog is one of the most important things you can teach. Doing so will help keep your dog safe and keep your mind at ease.
As with any command or cue to teach your dog, start the command at its simplest. See the links below to get the videos and details on how to start teaching a Come when called. Once your dog has the basics down and is reliable 90% of the time in your home or back yard, it's time to start practicing it out in the world with minimal or no distractions. Once your dog is doing well at this and responding 90% or more of the time, start adding small distractions. Remember to set your dog up for success. If the distraction you have tried adding is a little too much for your dog to ignore, try something they can more easily move away from. As the dog gets better with small distractions, start making the distractions more difficult. Remember to always move forward at your dog's pace. If the dog is making a lot of mistakes or unable to ignore the distraction you have tried, take the training back a step and make it easier until the dog can succeed.
Other helpful Blog articles:
Come when Called Step One
Come when Called Step Two
Come when Called Off Leash