Restaurant-style of meal prep:
"Generic" Raw Meats
I thinly slice a big batch of boneless chicken breast or pork sirloin chops, marinate in mixture of lots of lemon juice, salt and garlic powder (optional). I make the marinade very simple so it can be versatile in any dish. Wash hands before mixing. Stir it well by hand to distribute evenly. Cover. Label the date it was made.
Place in the coolest part of your fridge.
Proper food handling will keep it safe to eat for a week.
These will be good for quick-frying, or to add in sauté's or stir fry.
I cook a good portion of it (pan-frying) with sliced onions, and eat it with sour cream, and a dish of leafy salads. Left-over from this cooked portion can be divided into your lunch boxes, also stays about a week in the fridge (if handled properly).
You can also prep ahead food items that you use regularly in cooking (like washing and slicing onions, tomatoes, celery etc.,). You have them available for straight cooking!
Celery sticks make a good low-carb addition to a meal. I love it with home-made spinach dip made with chopped up frozen spinach (thawed and squeezed dry), softened cream cheese, sour cream and onion soup powder. This can also last for a week in the fridge.
I wash and prep it right away, cutting in desired lengths, and store them in a freezer bag in the fridge.
I use a heavy-duty freezer bag with double lock (I find it more sturdy for multiple use).
This freezer bag can be re-used. Label it and just wash it. I don't even dry it - stick it in the freezer and let the droplets of water freeze. I just shake those droplets of frozen water out when I'm ready to re-use it.
Use it only for vegetables - don't cross-contaminate with meats, or anything with oil!