Land is an interesting part of Magic. Too much or too little land means trouble, but having extra land cards in your hand doesn’t help either. Retrace is a great little Eventide mechanic that lets you use those extra lands. (Retrace - You may play this card from your graveyard by discarding a land card in addition to paying its other costs.)
Clash also helps with your land counts by smoothing your mana curve. (Clash - Each player reveals the top card of his or her library, then puts that card on the top or bottom. A player wins if his or her card had a higher converted mana cost.) While you may only win a clash about 25 percent of the time, at least you get to stack the top card of your deck. For better or worse clash also helps your opponent. Clash minimizes the negative aspect of land and smoothes your land counts.
Retrace is probably my favorite mechanic in Magic. Personally I think land is an old, arcane concept that Magic should get rid of. (Many people think Magic should also get rid of haste, but I like it.) I think you should be able to play any card as a land. A green card would be transformed into a Forest. The Marvel/DS VS trading card game does not use land and effectively lets you play any card as a land.
Retrace is good because it turns the disadvantage of extra land into an advantage. Although land is a necessary evil, Magic is still getting better and better. I can’t wait for Magic 2.0 (that’s a joke).