Congrats Nikitachi!
Pretty similar to everyone else, I overthrew Good Timers and rode out that confident moodlet to max Charisma asap, wishing well for promotions.
I actually didn't do any spamming before career level 4 since that's when Viral Video actually does anything and there aren't lower-level interactions that give enough followers to be meaningful. Instead I was making bank off of asking for loans for the 5k wishing well donations, getting the club and friend aspirations. I got all the skills I'd potentially need for promotion requirements meanwhile as well.
For the wishing well, I think the possibilities seem to depend solely on the face; if it's grinning or smiling/neutral, there's a chance of promotion, but only grinning seems to have 0 chance of getting demoted. 5k donations tend to auto-raise it to grinning. Idk if you can improve the stats by donating more at that point, maybe I'll look into it later. My practice consisted of finding that out by wishing 50x, so not foolproof, but yeah. So when I used the wishing well, I only wished if it wasn't already grinning.
I only got insta promotions for career levels 8 and 9, so way too late in my file for me to take full advantage of the most lucrative interactions. Tragic.
Broadcast status from the computer seemed like the best spamming thing (~10k followers)since it doesn't have cooldown. To take max advantage of Shout Out from XXX or the equivalents, I had my disguised sim go live at the Willow Creek Library and Broadcast Status from the computer and Shout Out whenever possible. My grind consisted of me shouting out/announcing appearance, broadcasting status 3x, then shouting out again. I was uploading viral videos, pranking streamers, etc. whenever I could, convenient since I was always sitting on a computer.
Fame came naturally with the constant status broadcasting, so I didn't do anything to help it along. I did accidentally lose a fame level temporarily because doing things in a celeb disguise doesn't give the fame it usually does, but I donated my wishing well last minute to fix that.