Hi Angie,
Personally I stratify in-situ and it has always worked well for me, although stratifying in the package has also been ok the couple of times I did it. Only limitation is that doing it after planting does take up a bit more fridge space
So, I would suggest:
1) buy 'potting mix' or 'seed starting mix' at store, NOT one with fertilizer already in it (read the bag).
2) sterilize w/bleach whatever container(s) you're using, rinse well, let dry.
3) fill w/ the potting mix you bought, tamped snugly but not packed hard.
4) sit filled containers in a dish of water (warm or hot, if the mix was quite dry coming out of the bag) for a few minutes or hours, whatever it takes, til water wicks up to top and top of soil feels damp / looks dark.
5) remove from dish of water, and prop up so the container can drip dry for a while (how long depends on how soaked it got), til it no longer drips much.
6) sow the seeds.
7) cover thinly with either a sprinkling of fine grade vermiculite if you have it or are feeling fancy, or a fine sprinkling of fresh potting mix (out of the bag, NOT presoaked) otherwise. Thin sprinkling means you can just barely, or better 'not quite', see the surface of the potting mix (and seeds) under tha layer you put on.
8) put carefully into clear plastic bag. close bag about 95%. Put in back of fridge.
9) put a note on the fridge or calender saying when to take 'em out... if no mention is made on packet I would stratify for 3 weeks. Is wise to peek once a week to see whether any seeds are sprouting - if more than 1 or 2 are, you should definitely end the cold treatment.
10) when time is up, or you see sproutage, remove and grow on as you normally would.
Who starts strawberries from *seed* though ??? ;P Is this pink panda or some other ornamental one?
Pat