Training your dog to pick up his own leash makes your life all the more simple but also gives your dog a fun trick to do. You can teach your dog to pick up his leash and bring it to you before walks or you can teach your dog to pick up his leash while you are walking him so he feels quite proud and accomplished taking himself for a walk. Teaching your dog to pick up a leash also helps dog owners who may have trouble picking something up from the ground when it falls. Your dog can hand his leash to you and tell you he's ready to go for a walk. This may keep your dog from barking and telling you he's ready to go when he has control over how he communicates his needs for walking.
Picking up his leash is a command your dog can learn quite easily with time and dedication. Much like teaching your dog how to fetch, picking up a leash will require repetition and work with the leash at hand. You can work on picking up a leash in your home before you go for walks, or you can work on picking up his leash while you are actually on walks and using the leash together. Once you've taught your dog how to pick up his leash and what his leash is, you could even keep his leash in the same spot every day and he can go get it and bring it to you when he's ready for a walk.
You will obviously need a leash that is a suitable size for your dog. A collar or a harness for your dog will also be necessary to attach the leash to. Consider harnesses for large breed dogs or dogs who can pull and are possibly out of control while on a leash. Your dog is going to need some high-value treats to learn this trick. Keep him engaged and enticed with something like cheese or hot dogs. You will need time to take your dog for walks while doing this training, so make sure you schedule training sessions every day so it's always fresh on his mind and becomes part of your daily routine.