My working springer puppy is still only 6 months old but the most important things I've learned since getting him, from various trainers and online resources: crate training, enrichment (snuffle mats/lickimats/chew toys/stuffed kongs) and not over exercising them. Multiple people have told me not to over exercise him as he'll just turn into an athlete who needs more and more exercise and it'll be harder than it needs to be. I agree with the other poster in here who said their dog calms down after 10-15 mins off leash - I definitely see the same. He's absolutely full of beans but I throw a ball in an enclosed space for 15 - 30 mins and hell happily walk home beside me and barely pulling on the leash. I also take him into dog friendly shops and cafes to get him used to different environments, socialise him and tire out his little brain. They are high energy so the more prepared for that you are the better, but it definitely doesn't mean you need to be an athlete out with him all day. There are various ways to work them.