There are a few ingredients that are in hundreds of recipes; keep your options open by keeping plenty of them on hand and keep your budget lean by buying them in bulk and prepping them yourself.
Step 1: What You Need
This one is simple and it may seem silly, but it is amazing how much time and money it saves you. Basically what you are doing is making your own frozen vegetables for quick home cooking; it is often cheaper to buy fresh and freeze it yourself and this way you are able to have varieties that aren't normally found in stores (like frozen onions or tomatoes). this way you only need a few extra ingredients and the rest of your meal is chopped and ready to use. All you need is: cutting board and knife, cookie sheet or something large and flat that will fit in your freezer, a freezer, reclosable bags or leftover containers, and the the ingredients you will be using. My favorites are onions, garlic, tomatoes, broccoli, rice, and various peppers. these are my favorites because they are in so many of the things I like (Italian, Mexican, Indian) and because they freeze well, but you should pick ingredients you commonly use. be sure to buy in bulk wherever you can to cut costs.
Step 2: Prepping for Freezer
for the rice, start out by cooking it as if you were going to use it today, cook as much as you pot or rice cooker can handle- the more you do the less often you have to do it. for the vegetables, first wash and chop them up, smaller is better because it will thaw quicker but if you prefer cooking with larger chunks then cut them larger. once the veggies are cut spread them on the cookie sheet, the same goes for the rice once it's cool enough to handle. put the cookie sheet in the freezer for about 30 minutes.
Step 3: Bag It Up
take the cookie sheet out of the freezer and scoop your now mostly frozen veggies into the bags or containers. for some you may have to scrape them off with a spatula. put the bags into the freezer and use them wherever a recipe calls for them or make up your own recipe based on what you have on hand. for the rice all you need to do is add just a little bit of water and microwave for about a minute and a half, or its great for making fried rice. I also like to put it into several small containers so that they are individual serving sizes.
Step 4: Little Bonus Recipe
I don't do a lot of measuring so I will give approximations, but feel free to change it as you like.
first get some water boiling for cooking some pasta. while you wait for the pasta get out some butter, your frozen garlic, onions, tomatoes, and broccoli. put the broccoli in the boiling water with the pasta. in a big frying pan or wok heat up the butter( about 1/2 tbsp) and sauté the garlic (about 1tsp). once it's barely golden brown add about 1/4 cup of onions and continue sautéing until the onions start to caramelize. add the tomatoes(and any other veggies you want, peas are good) absolutely mix it all up. once the pasta is soft drain it and put it and the broccoli into the wok and stir it all up. add a little bit of whatever kind of cheese you like and some fresh spinach and basil and give it one more quick stir to combine evenly and enjoy. the longest part of this recipe is waiting for the pasta to cook and it is just one example if the many possibilities available to you.