My boyfriend (same guy since 2008, I'll refer to him as Tek) and I got some new magic cards. We were talking about mana. He didn't understand why, if we're on the same battlefield, we have access to different types of land. I explained how the players were the original planes walkers, and our home world was a different one where the battle was taking place. As I understand it, we get our energy from our home world, not our battle world. He then wondered why we can't tap the battlefield. We came up with a house-rule; battlefield mana.

At the start of your turn, roll a d4. That is the amount of uncolored mana you got from the battlefield that turn. Land still works as normal. 

We've played a few games with this, and it really enhances the game. Our games were usually either five minutes, or three hours. Now they're 15 mins to an hour. Comebacks were a thing in about half our games, instead of once in a blue moon. Strategies had to be made on the fly, since you didn't quite know how much mana you would have next turn. Cards I normally wouldn't be able to play with the low amount of mana I had were suddenly playable. But since the mana was uncolored, if I only had one mountain, I could still only play one red card. All in all, it was a rousing success, and made the game fun again. Even against the deck I couldn't beat. I highly recommend everyone try playing this way.