I personally and this is IMO and what has worked for me when stuck in very cold/snowy weather perfer to take off in 1st but switch up straight away to 2nd or 3rd. I find the car lurches less and if you need a little throttle to get it going in 3rd or second to stop it from stalling its kinda pointless IMO.
If you are going to use the brakes try to do it slowly and steadly e.g. like there is something soft under the pedal. Keep de icer a scraper and warm clothes handy too.
The best piece of advice is if its snowing and you have got winter tyres double or treble the time you think the journey will take and leave early so you don't rush. If you don't have winter tyres maybe 4-5 times the time it would take.
Keep your distance from other cars. Also look at the driving style and behavior of other drivers. See someone driving like a prat let him pass you so he can crash in front of you not into you.
Make sure your screenwash is diluted properly.
Try not to brake hard enough to activate ABS otherwise you will slide all day.
But honestly honestly if its pretty bad and you don't have winter tyres, stay home or use public transport (if its running). I think winter tyres are great as before driving in winter was an @rse clenching experience.