I'll be following this nice table that user Shirluban also posted in the aforementioned recent thread.
Note: I don't have a group of people to play mahjong regularly, but the following is how I would like it to explain it if I had one. Of course, I am aware that when playing on a league or tournament, you can't really select the rules you want.
- Kuitan-Atozuke: Ari Ari (or in english, both are allowed)
- Kuikae Nashi
- 25000 starting points, goal is 30000. Uma is 20/10. I find this values all positions in a nice increasing scale, 30 from 1st to 2nd, 20 from 2nd to 3rd, 10 from 3rd to 4th
- Uma is divided on ties. On rare 3-way ties I would go with 7 each, increasing the 20 uma for an extreme position to 21
- Riichi bets go to the last winner (They go to the winner anyway all the time, don't they?)
- Renchan tenpai. Agari/Tenpai has some merits. That flash version I use sometimes seems to have Renchan positive, which means if all four players are tenpai, winds move.
- Standard 300 points continuation, 3000 points noten
- All doras are in, red fives (if the set has them, of course) should be 111
- Ron, Pon/Kan, Chi preference. All rons accepted and paid
- Temporary furiten ends with your discard, not a skipped goaround
- Ryanhan Shibari I'm ambivalent at the time, really. Probably included
- No abortive draws, only four kans allowed. I can understand the four riichi one, but then, fourth player knows the situation and still can choose whether to riichi
- Pao on three dragons, four winds only. The continuances are paid by the discarder (I hadn't really thought of that). Rinshan Kaihou is tsumo
- Agari Yame I'm a bit ambivalent too, but tending to a Nashi
- Bankruptcy on -100, you need to be able to afford the riichi stick.
- West round sudden death, overflowing into North if needed. I like the CRM rule on ending only on a win (BUT if it's an oya win, the game goes on, if Agari Yame is off)
- Yakitori, Wareme, Aotenjou are all Nashi
- Kiriage Mangan Nashi
- Kazoe Yakuman is on, multiple yakuman stack, but of course Kazoe is incompatible with them, because you don't count han on a yakuman
- Furiten Riichi is OK, but you need a theoretical next draw (it could get skipped, that's not your fault)
- Ankan after Riichi only if it doesn't change the hand structure or wait
- Chankan for 13 Orphans not allowed. All Green can be dragonless
- Haitei Rinshan is NOT a thing
- Nagashi Mangan is a yaku
- Keishiki tenpai is OK, but not a 5th tile tenpai
- Open Riichi Nashi
- Standard Yaku values. Although not technically true, I would explain Ryanpeikou as 1+1+1, as I think it makes it easier to understand and more consistent with other yaku
- Daichisei is double yakuman
- Shiisanpuutaa and Shiisuupuutaa Nashi
- Paarenchan... no clue. It's complicated. No other unusual yaku
- Standard fu count. Chiitoi is 25, "open pinfu" is 2, Rinshan is a tsumo, tsumo fu voided if pinfu yaku scored, double wind is 4