I have a vacuum heat sealer that I use with these bags. As the inside is smooth, it does not get all the air out, (The real ones have a very fine cross hatch inside but are a lot dearer.) I make a meal or two seal the bag and freeze them. In the field you can seal with a peg or a bit of thin string after popping what you like in. Its even worth warming a tin of beans (contents) in one to save on washing up.
Just bought 4 x 6m rolls of the Fresherpak embossed stuff for £20 from eBay. £5 for 6m of tube is good value, the embossing allows better air removal. I use mine to pack biltong, though we have some sausage, salmon and even soups in the freezer. The Fresherpak vac is a great machine, but as with any vac packer, liquid stuff needs to be more carefully bagged or part of your food will end up in the machine. It does make an excellent seal though. Apparently Sous Vide cooking is quite vogue these days too. Marinade your salmon in whatever (teriyaki, chilli, garlic, ginger, coriander) for a bit. Wipe dry and vac. Freeze til needed then drop in hot water. Easy to make up big batches.
For my next night out, it's the bagged omelette. I haven't tried that yet.