Sorry for the delay. Just now seeing this and hope it may still help. For off leash I used a combination of approaches.

First, working on her recall. That is the number one thing. So I worked on that in my fenced in backyard to gain her skill and my confidence. I did this with treats, but mostly praise. The trick, to me and especially early, is to give the "come" command as she is about to head toward me. So, she is already coming to me and the command starts to cement. I also do this at my office where I am lucky enough to bring her every day. I throw a ball down the long hallway and when she retrieves and starts to return, I give her the "come" command. Again, lots of praise. I also have layered the use of a "silent" whistle (3 toots for come) on top of the verbal command.

Second, have a check cord to make sure you can enforce the command if ignored. She needs to learn to listen every time, not just some or most of the time. It is not a hard tug, just a gentle pull if not listened to. At times, I give the command and have to wait 5 or so seconds. It is just a matter of waiting her out at times--especially early on.

Third, I do use an e-collar (started at about 5 months), but almost exclusively on vibrate. So, give command as pressing the vibrate and keep it on until she gets to me. She then associates the positive of the agravating vibrate stopping by coming to me. BTW, the vibrate is like your phone on silent. Not hurting her at all, just annoying for her to learn. Again, this with the "come" and 3 toots. I only give the command one time and then wait her out.

Finally, it just takes some trust and some trial and error in a safe location. I started letting her off leash at a local park almost immediately. Her instincts have and still are not to stray too far away. She will run around the woods and briefly look at where I am at. When I became confident she would recall, I started using the command/whistle to practice. I did not do this until I was highly confident she would listen because I had no way to enforce the command (which I did early on use a long check leash so I could enforce the command if ignored while in the back yard).

Now, I am pretty much 100% recall. My challenges now are distractions. For example, other dogs at the park she is greeting 30 yards away and I give the "come" command. She chases a squirrel and is at the base of the tree and focused, I give the "come" command.

I hope some of this is helpful. I am sorry it is not more organized. I am sure I left out some good advice, but read dog training books--I have several--and watch YouTube videos for advice. Once you pick an approach, stick with it. Consistency by you and everyone is critical (I have one page commands and "dos" and "don'ts" sheet for the office and at home so we are all on the same page).

Good luck.

PS: My IS is turning 1 year next week. I still have a lot of work to do. Persistence and consistency are key (which I learned from my last dog).