There is probably a better way, but...
I bought a 1 lb kicker at LHBS (duh, I could have used runnings from the MLT!) and divided that into eight portions. I keep 'em frozen in little tupperware-like containers until I need 'em.
When ready to make a starter, I fill my Erlenmeyer flask about 3/4 full of water and boil for about 15 mins. I just put it right on the burner. It will boil over, but it's only water, and it gets the boiling water over the lip.
Then, using silicon-tipped tongs, I pour out most of the water (I measure with two fingers--just eyeball it), and then add the bit of frozen malt. Boil again for about 15 mins. All this boiling sanitizes the flask and the malt. (Some people add hops to this mini wort. I don't. You don't need flavor here, just fermentables.)
Let cool on its own down to pitching temp. Then flame-sterilize the lip/spout of the flask. Pitch yeast. Give a gentle swirl. Put on sanitized stopper and airlock. Place on stirplate (or just swirl gently a few times a day). Wait till you have enough to pitch in a full-sized batch, 3-5 days. You'll need to flame-sterilize the lip/spout again before pouring out the starter.
If you have a large flask you can add more wort/malt (as long as it's been boiled and cooled) after a day or two. Remember to flame-sterilize the lip every time you take off the stopper. Or, if you have multiple flasks, just have two going at once. Rotate them 12 hrs each on the stirplate, unless you have one for both.
I used to do this religiously until I got behind on my brew schedule (work! you know how it is) and forgot to make my starter for a strong scottish I was waiting to brew. Brew day came, and I had to brew--I wasn't going to have a chance for another two weeks. Got impatient. I just aerated the heck out of the wort, pitched from the vial. Had a strong fermentation. OG was 1.074.
But if you have an O2 system, and a stirplate, then, wow, you should have one helluva starter and a great fermentation. Good luck.