Materials to Have On Hand

A pressure cooker or canner, to heat sterilize your tools A good supply of sterile disposable plastic Petri dishes (10 cm diameter), poured with agar/malt solid media. As an alternative you might want to use glass Petri dishes, which can be reused as many times as you want, but need to be sterilized in an autoclave
	Screw cap culture tubes (best size is 18x160mm), filled with wort and sterilized (autoclaved) Screw cap culture tubes (best size is 16x100mm), filled with 6 ml of distilled water and sterilized (autoclaved) A good supply of sterile canned wort, for use as starter media, preferably in 50, 250, 700 ml sizes
Inoculation loop. An aluminum rod handle carrying a nickel/chrome steel wire about 7 cm long, terminated in the form of a 3-4 mm loop. You can make one yourself with a length of Ø 0,5 mm steel wire and an X-acto handle.
	1 ml glass pipettes, sterilized. They should have a cotton plug on the mouth end, to keep your mouth bacteria out
sterile 100 ml Erlenmayer flask, or small bottle, with screw cap, rubber closure, or glass cap (best) sterile 500 ml Erlenmayer flask, or bottle, with screw cap, rubber closure, or glass cap sterile 1000 ml Erlenmayer flask sterile airlock with rubber bung, fitting the above 1000 ml flask Sterile disposable 5cc syringes
	A good source of flame, either a Bunsen burner or a handheld propane torch

The Flame Zone

We will be using a flame to sterilize the inoculation loop and the openings of various containers.
As you can imagine, direct contact with a flame destroys bacteria, molds and spores.
But there is a second advantage to the use of a flame: it heats the air immediately surrounding it, creating an ascending air flow.
At a distance of less than 5 cm from the flame, we are inside this protected area called the flame zone, in which it is very unlikely that any airborne dust particle may fall.

Alcohol

Even though alcohol is an inadequate sanitizer, it is always good practice to use it to wipe the outside of the glassware you'll be using, to remove dust particles that may have accumulated.
CAUTION: alcohol is extremely flammable, wait for complete evaporation before lighting any flame!

Speed

All procedures should be performed as quickly as possible to minimize the chance of contamination.
Practice, practice and then practice some more.
Also, remember to work in flame zone, if at all possible.

Multi Strain Yeast

There is no easy way for a non professional to maintain a mixed-strain yeast: if you use plating to select colonies, you will probably end up with only one of the strains of which the mix is composed.
So I advise you to stay away from such yeasts. After all, a brand new Wyeast pack costs only a few bucks...