I usually double up my recipes so there is always something in the freezer, eg., hamburgers, soup, LC pita pizza (ready to toast), goulash, flax muffin with cold cuts and cream cheese, etc. Knackwurst (german sausage) and sauerkraut is a quick go to for me as well.
When Im not in the kitchen (or have access to my freezer) I usually eat out. I end up with sandwiches on croissants, then remove the croissant and turn the end items over (lettuce on one side, cheese on the other), or go for a Cobb salad from places I know use a low carb dressing. If I run by whole foods there is a large selection for lunch, but you have to watch out for those hidden carbs in their food (korean pulled pork is a good example). I sometimes end up buying double entrees to make sure I get enough fat / protein (el pollo local its a twice grilled burrito, loose the tortilla, then a plain salad with ranch).