Ingredients For 1 folded kimbap (only an example)

1/4 cup cooked rice
1/4 teaspoon sesame oil
salt to taste
1/4 teaspoon sesame seeds -- optional
1 gim (김밥용 김), seaweed sheet (aka laver, nori)

For proteins

2 thin slices Spam or 2 tablespoons canned tuna (press out the liquid) or other cooked or processed meat
1 fried egg (no runny yolk) or cheese, eomuk (fish cake), fried tofu, etc. 

For vegetables

1 lettuce leaf you can use 2 or double up with a perilla leaf
1/2 small cucumber or carrot or your choice of veggies thinly sliced or julienned as necessary

Instructions

Mix warm rice with a little bit of sesame oil, salt to taste, and optional sesame seeds
If using Spam, thinly slice and pan fry for a minute or two on each side over medium heat. If using leftover cooked meat, you can heat it in the microwave as necessary. If using canned tuna, press the liquid out.
Clean and pat dry the vegetables with a paper/kitchen towel. Thinly slice, shave (with a peeler), or julienne the cucumber or carrot. You can lightly sauté the cucumber or carrot, but not necessary. If using kimchi, thinly slice and squeeze out the liquid. You can mix kimchi with sesame oil and/or stir-fry in lightly oiled pan, but not necessary.
Put a sheet of nori, shiny side down and shorter side towards you (the photo may not look like that because of the camera angle), on a cutting board or plate. Cut a slit to the middle of gim (seaweed sheet) from the short side.
Spread the rice evenly over the bottom left quarter of the seaweed sheet. Arrange the other ingredients on each quarter. Lift the bottom left quarter and fold it onto the top left quarter, then to the top right, and finally to the bottom right. Press lightly and tuck the filling in after each fold.

Notes Tips for folded kimbap

Squeeze out the liquid from any wet ingredients.
Pat dry vegetables with a paper/kitchen towel.
Don't overload it! It'll be hard to fold and eat. Leave some space between the quarters for folding.
You can double up the ingredients on each quarter as long as they are not too bulky.
Place small pieces or easy to fall out ingredients next to the rice one. The sticky rice will help hold them together.