Gameplay mechanics - Things like rulings and missed timings are a bane to most of the duelists of ODA.

All 3. Why?

You're supposed to teach people how to play the game and have all the qualities an Obelisk Blue-worthy players have. A legit Obelisk needs to know all 3 of those things like their shoes, so that they can, in the future, even possibly get into Orichalcos.
I could help a bit with Ruling Lessons, etc, if you want.

I think what we really need now is game play mechanics, be it rulings, timing, or something completly diffrent. The top tier is fairly limited at the moment, so no reason to go further into that. Instead try to go from the very basics, or what should be basics and yet a lot of people mess up.

I suggest taking advantage of the many teachers we have to get all these done  also I think we should have a ruling lesson. I'm.....not to great at those. Or a lesson on when to play cards cause that can be crucial.

For Game Play mechanics Rulings would be good to have as a lesson, I personally am not bad with rulings but seeing how I did on my test rulings did give me an issue so I would love to have a lesson on rulings.

I think all three is a given. However, we obviously need to start somewhere, since we can't realistically fit all that into one coherent and useful lesson. So, I say we start with deck construction tips. That's just me, though.

How about "Countering the Rouges" since 60+ percent of the competitive scene is the big decks  its just as important to know how to counter the other decks you will inevitably face thi could be done by constructing a side deck vs a variety of rouge decks with cards that could help take down multiple rouge decks...decks they would have poor matches with outside of the meta  and stuff like that

The only problem with that idea, Kev, is that statistically, only around 11% of the competitive scene uses non-Meta. I suppose it's about the same as Verz, but there are so many Decks to cover that it gets rather ridiculous. I suppose a lesson on, as ridiculous as it is, countering the anti-meta >.> Covering the cards and combos people will run to try to get over the number 1 Decks. But that almost seems redundant.

Statistics for competitive play I believe is close to this: 44% Dragon Rulers ( E-Dragons ), 33% Spellbooks, 12% Evilswarm, 11% everything else.

well if the point is to come up with new ideas for lessons facing rouge decks will satify that need ....and bear in mind the meta now will not be the same in a couple months when the ban list is dropped and new sets are put out  so it is important to keep up on other decks at least the tier 2 and up that people still play pretty often ....also the other idea was building a succsefull side deck  meaning u could give a list of say 5 decks  and then we would have to use the 15 cards including extra copies  to battle all of those decks as best we could think of with higher points for cards that cover multiple decks at a time

I was also thinking something, playing a Slifer earlier today.  There should SERIOUSLY be a lesson on WHEN to use MST... I see it being used blind in nearly every duel, and that is a waste of a perfectly powerful card.