Just a bit more info on yeast preparation that might come in handy:
i) You should always aerate the wort (ie stir the crap out of it, pump air in through an aeration stone, or pump in O2 through an aeration stone if you are really lucky ) and the higher the OG the more critical this becomes.
Note if you are doing what I am which is just stirring the crap out of it you need to me a little mindful that there is not too much airflow ( risk of wild yeasts, bacteria spores etc dropping in ) and preferably indoors. Note I have had no infections from doing it this way yet.
I usually do this after pitching the yeast. Really it wont hurt them, and after all they are the ones that need the oxygen, not the wort.
ii) Always hydrate your dried yeast in warm (not hot water) before pitching.
Being dehydrated the yeast will suck in whatever liquid you put it into, without being able to filter it. If this liquid happens to be chock full of sugars (ie wort ) it can burst the cell walls and kill off some of the yeast cells. So you are making it harder for the yeast before you even start.
Its a bit like throwing someone out of a moving vehicle and expecting them to start running. Much easier if you stop first and then let them get out.
Note this is a very very very very ( have a put in enough verys ) LOW sanitation risk. (Because you are of course going to do it in a presanitised container, with water that has been boiled then allowed to cool down right?)