To make your yeast starter, two or three days before brewing day gather:
Glass jug - one quart to a gallon is fine. I use a 2000 ML FLASK
Dry Malt Extract - light/dark doesn't matter. There won't be enough to affect your final brew.
Small sauce pan and lid
Airlock
Rubber Stopper that fits your glass jug
Sanitizer-- use a good method and sanitize everything including the work area
Small Thermometer - Candy thermometer is perfect
Yeast
Just like brewing a regular batch of beer, you'll need to start with wort. Here, though, you're only interested in providing lots of sugar for the yeast to feast upon so no hops nor adjuncts will be added.
1--Put half a cup of dried malt extract into your sauce pan then
2--add about a cup of water. Boil for a couple of minutes to make sure it's sanitized keeping the lid on as much as possible to prevent too much evaporation. Watch out for boil overs ((( I make a double batch but with one yeast pack/bottle only))
3--cool to 60 to 72 Fahrenheit for ales and 46 to 55 degrees for lagers.
4-- Put the airlock on the bottle the. Agitate the wort so it will be properly aerated(( I use a fish tank agitator on both my bottle and total batch of wurt)))

5- Add the yeast.

6- In a day or less you should start to see active fermentation. The airlock will bubble but you won't always see high krausen, the billowing clumps of foam that form during regular fermentation with a full batch. What's important is that you will start to see an ever increasing deposit of yeast at the bottom of the jug. By brew day you should have a thick layer of eager yeast, ready to give your beer a head start. Make sure to get it all into your wort.

Using a yeast starter like this will produce fermentation in less than a day, sometimes even hours after adding. Good luck and happy brewing!