1. Use a good quality matcha
A puff of vibrant, fine green powder with a sweet, grassy aroma indicates that you've opened a good tin of matcha. Don't bother with matcha made anywhere but Japan. Lumps are a sign of good quality.
2. Have the right equipment
You don't need all the fancy tools used for a tea ceremony, but you do need a matcha bamboo whisk (chosen) and a bowl or wide teacup that allows plenty of room for whisking. A tea strainer is also useful to avoid lumps but not essential.
3. Use hot, not boiling water
Even if you want to make iced matcha or a matcha latte, the tea will dissolve best in hot water. However, avoid using boiling water - it shouldn't be over 80°C as boiling will degrade the nutrients and could result in making the taste bitter.
4. Get the right ratio
1 gram of powder (1/2 teaspoon) to a half or two thirds bowl / cup of water makes the perfect cup.
5. Whisk vigorously
Once the matcha powder is in the bowl add a small amount of hot - not boiling- water (no more than 80°C) and whisk back and forth in a zig zag with the bamboo whisk lightly touching the bottom of the bowl / cup to create a smooth paste and then add more water and whisk again. When the tea is thoroughly mixed with the water and is frothy drink it right away. If you sift the matcha through a tea strainer you can simply add all the water and whisk.