Making a homemade Buzz Lightyear costume might look complicated, and if you're going to make an exact replica you might have a hard time, but making a great seeing Buzz costume with some very basic items isn't as complicated as you might think.
What you need:
White Sweat Pants
A Black or Purple Undershirt
A White T-shirt or sweatshirt that you don't mind cutting
Needle and Thread or Fabric Glue
White, Purple, Red and Green Spray Paint
A picture of Buzz for Reference
Although Buzz's space ranger outfit looks complex, if you focus on the key details you can generate an easily recognizable look alike. Start with the black shirt. This will serve as the base layer and contribute the middle diction of the outfit. Take note of Buzz's white chest protector. It consists of white armor with a green plate, where his buttons are, and two purple stripes that circle nearby to the back side.
To make the armor, you can cut the bottom off of a white sweatshirt or t-shirt. A sweatshirt will work great because it provides a heavier look. You may also want to fold the frayed bottom of the sweatshirt under and sew it to the black undershirt. This will help generate the armor look.
The green chest plate can be made by cutting out a patter from the green fabric. Attach this patter to the white armor, and add buttons onto the green fabric. If you are feeling easily ambitious you can even make a Star Command logo to mount in the middle. Attach the purple stripes underneath the green chest piece and run them along the side of the white shirt to the back. You can quantum the distance for the purple stripes with a piece of string. Hold one end of the string where you want the stripe to start, commonly right under the green chest plate, and then loop it under the arm and to the middle of the back.
If your white top shirt did not have sleeves, you might want to make your gloves longer to make up for it. Your Buzz Lightyear costume does not have to have gloves, but it will help faultless the look and prevent dinky ones from getting cold hands on Halloween. Any white gloves will work, although a plastic like material is preferred. The back of the hands should have a green piece of fabric on them which extends from the wrist to the knuckles. Buzz also has purple accents at his finger joints, but this isn't a necessity. The sleeve end of the glove should have a green stripe nearby it, or if you have long sleeves you can put a green stripe of fabric nearby the elbow.
Buzz's pants are much simpler than his shirt. Any white pair of sweatpants will work, although it helps if they match the white sweatshirt you used for the top. Make a small knee pad shape and attach it to the knee of the pants. There should also be a stripe that that wraps all the way nearby the pant leg from the knee pads.
Buzz wears white shoes with green nearby the ankles, but you can trim the bottom of the sweat pants with green and wear anyone shoes you like.
The Jet Pack
The jet pack is relatively easy to make, but it can be time consuming. There are many distinct ways to create the jet pack, but I prefer using a backpack and attaching wings. This makes it easy to get the jet pack on and off, and it can save you a ton of time. If you can find a white backpack, paint two green stripes on the side and a purple stripe down the middle. Don't worry too much about making the backpack super detailed, as the normal look is commonly good enough.
Cut the wings out of cardboard. I would propose making them slightly smaller, as they will be more stable. You can reinforce the wings by running small sticks along the inside distance of the wing. Paint the main section of the wings purple. You might want to tape off a line along the top of the wing to make it easier to paint later. Buzz has small green pods on the end of his wings, and how in-depth you go is up to you. You can cut these pods out of foam, or make them flat and cut them out of cardboard.
The top edge of Buzz's wings has an alternating red and white patter, much like a candy cane. If you're going to paint this part, do the white paint first so that the red will show up better. You can generate this pattern using pieces of masking tape. If you paint the whole stripe white first, then you won't have to do manifold tape jobs. The wings can be stapled onto the backpack.
To Halloween, and Beyond!
That's pretty much all things you need to make a homemade Buzz Lightyear costume. You can also add a purple hood if you can find stretchy fabric. If you don't want to make the jet pack out of a backpack, you can also use Paper Mache, or even cut something out of cardboard. This how to make a Buzz Lightyear costume guide will ensure that you have one of the most "out there" costumes this Halloween.