When I'm not exploring fresh caves or lands in minecraft, I'm busy trying to find deposits of diamond, gold and iron deep in the earth. So far I've just been digging around just above bedrock on a whim to look for these rare minerals but I've started thinking that I should be taking a more controlled, efficient approach to mining.

**What is the optimal mining strategy that yields the most rare minerals while minimizing blocks removed and time spent digging and traveling?**

**Edit:** The existing answers are great for mining, but no one has addressed travel time to and from the mine which is usually ~60 blocks downward and incredibly tedious. Solutions?
['https://gaming.stackexchange.com/questions/8310', 'https://gaming.stackexchange.com', 'https://gaming.stackexchange.com/users/1070/']
Dig down to bedrock with a staircase. Then make a room about 10 by 10. Finally branch out on each side of the wall. Pick one side and go with it untill it is to long. Then get another side. Once all four are branched, branch off them. I now have about 15-20 BLOCKS of diamond 20-23 BLOCKS of gold like 30-50 stacks of coal no red (I don't mine it just go around) and 40-45 BLOCKS of iron all totaling about 7 hrs of work
The easiest way to mine is to mine a 2x2 tunnel horizontally. You can cover 8 blocks that way, with the same amount of blocks mined as a branch mine, which only reveals 6 blocks. As for getting up and down, use a water fall cushion (to jump into, must be 2 deep) and a water LADDER (check the youtube videos to see what it is).