I mix in browned ground beef. Sometimes I'll slice kielbasa and saute it to mix with it. You can also get a bag of frozen veggies (California mix of carrots, broccoli, and cauliflower is great) to add. My favorite is ground beef and peas.
Mac and cheese fried balls!
Make pasta and mix in dry cheese, add some flour and corn starch seasonings as needed, roll/ scoop in balls, freeze. Roll in eggs, roll in breadcrumbs, fry in oil of choice until golden brown!
Also, I love making it into a casserole. Growing up we’d mix in a can of mushroom soup, a can of peas, and a can of tuna. Now as a variation I sometimes throw it in a casserole dish with Panko crumbs on top and some shredded cheese!
Brown a pound of burger in a pan. Make 2 boxes of mac n cheese in a pot as directed. Once the burger is almost done, I toss in a can of sweet corn to heat up. Once the mac n cheese is done and the burger/corn mix is heated. Combine the two. Add salt and pepper to taste. It's like a crafted hamburger helper. This is a childhood comfort food
Taco pasta - ground beef or chicken, steak etc - brown and season to taste. Drain if needed, add 1 pack taco seasoning and follow directions on pack. When done add in 1 can rotel. Mix with the macaroni and cheese (cook this as you usually do) - it’s a fav for my kids. I add in extra onion too but you don’t have to. You can usually make this for under 10 dollars