not having a routine does not mean not having a plan.
It just means that i cant predict what the numbers are on a particular day - i will have goals, but the progression is not based on paperwork and predicted progress (never really worked for me anyway), i will know what my main targets for the session are before hand - very important for the visualisation and mental prep to have that.
I also know more or less what i will do on what day - days will vary because life is like that, or you may have some niggle or recovery problem and you cant do the usual stuff on usual slots. Especially if one does strongman and nails fair few comps, like i did at least 8 last year, plus big meaningful sessions, it needs the days off beforehand too.
My outline is more or less like this at the moment:
day 1. overhead (jerk, push press, strict, with various things, these will vary and aim to progress in each with each implement)
day 2. squat/deadlift (or both), and variations: partial pulls, stiff legs and so on
day 3. press again
day 4. events
usually have 1 or 2 main lifts with main targets for the day, then some kind of assistance work, and leftovers in the end if ammo, or time, or need.
Volume, rep range and so on vary depending on the time in the season, like over winter i wanted to pack on muscle so i did more high rep work, closer to comp i vary between top end strength for events which need it, and repping for others - always vary again.
hey it sounds more complex now that i write it down rather than "i go to the gym and lift"