I call this rule set the Squared-Rooted Rules because my goal is to reduce the approximate number of games significantly affected by mana-screw/mana-flood/color-screw. Suppose about 16% of games are made sour by random mana-problems. This rule set will ideally reduce that percentage to about 4%, and 4 is the square root of 16! Well, that's the ideal premise. Whether it turns out that way remains to be determined. More importantly, having a gimmicky title serves as click-bait.
Anyway, the rule set is as follows:
1. Any time a player has priority, they may exile two land cards from their hand to draw a card.
2. Each colored mana symbol in a mana cost can be paid with either one mana of that color, or by paying 2 generic mana.
Rule #1: Reduces the likelihood of mana-flood and mana-screw. Obviously, losing two cards to draw one card is unpleasant, but at least it's better than being stuck with nothing but lands and consequentially no spells to cast. It also slightly reduces the likelihood of mana-screw, because you will probably want to include a few more lands in your deck, knowing that mana-flood won't necessarily dictate defeat to the same extent as in plain MtG. Also, because you exile lands rather than discard them, I can't think of decks that can profoundly abuse this rule.
Rule #2: Reduces the likelihood of color-screw. It also opens up your drafting options a little bit, making it more appealing to draft a 3-color deck. This makes you decisions while drafting packs #2-3 less restrictive, which also allows you more opportunity to draft more skillfully (or more ineptly) than the other players at the table.
I would set number 1 to be limited once a turn and only on their turn to limit the ability to make it combo oriented. If the goal is to reduce screw or flood there's no real need to be multiple times a turn and on the opponents turn.
Anyway, the rule set is as follows:
1. Any time a player has priority, they may exile two land cards from their hand to draw a card.
2. Each colored mana symbol in a mana cost can be paid with either one mana of that color, or by paying 2 generic mana.
Rule #1: Reduces the likelihood of mana-flood and mana-screw. Obviously, losing two cards to draw one card is unpleasant, but at least it's better than being stuck with nothing but lands and consequentially no spells to cast. It also slightly reduces the likelihood of mana-screw, because you will probably want to include a few more lands in your deck, knowing that mana-flood won't necessarily dictate defeat to the same extent as in plain MtG. Also, because you exile lands rather than discard them, I can't think of decks that can profoundly abuse this rule.
Rule #2: Reduces the likelihood of color-screw. It also opens up your drafting options a little bit, making it more appealing to draft a 3-color deck. This makes you decisions while drafting packs #2-3 less restrictive, which also allows you more opportunity to draft more skillfully (or more ineptly) than the other players at the table.