A yeast starter allows the yeast colony to grow before pitching which decreases latency for yeast to begin fermentation and increases completeness of fermentation.
½ Gallon glass jug and S-style airlock with stopper
¼ Cup Light Spray Malt
¼ Teaspoon Yeast Nutrient
Sanitize glass jug and airlock and funnel with your prefered sanitizer.
Bring to a boil: 1 quart (¼ gallon) water, ¼ cup malt, ¼ teaspoon nutrient. Watch out here this will try and boil over on you if you don't watch carefully!
Funnel the liquid into the sanitized jug and cap with your airlock.
Place the jug in a refridgerator or freezer untill it is within the temperature range listed for your yeast strain.
Uncap and pour your yeast culture into the jug and recap.
Maintain desired temperature while wait for yeast to show signs of increased population.
Pitch into primary fermenter during high krausening (strongest fermentation). High krausening is the stage at which your jug will be come quite hazy with yeast but they will not have flocculated and formed a cake on the bottom of the jug yet. This will generally take about a day but may take as little as a few hours or up to two days. If you are a good brewer you will be prepared and brew at optimal time for the yeast, not for you, which will result in the strongest and most complete fermentation possible.