I have ranged between 82kg at my max and 60kg at my lowest the last 10+ years of so most of it below 70kg (I'm 1.72m) so I kind of know the swings and what to expect in terms of weight loss based on what I eat and do. That's how I set goals. I just see what is 'easly' eachievable without going into any extremes. The biggest challenge tends to be to go into maintenance mode as so far it has always been a switch between really eating healthy or letting myself go. This is the main thing I'm trying to get right and fix over time.

Also I don't have a dayjob so that makes it a whole lot easier as I'm not dealing with any stress or time / energy shortage. What I would say really helps a lot is just keeping this daily blog as it's like looking into the mirror each day and it has helped me from drifing away too far for too long.

I would say start today already with baby steps, procrastination also has been one of my major flaws.
Good luck!