How do you roll a burrito?

the trick is not to put in too much filling. so, put in beans, rice, meat, veggies in a horizontal stripe down the center of the flour tortilla (about 1/4 of the area), fold over a bit from the sides, and then roll together.

The amount of filling is directly related to the size of your tortilla. You can usually do about 1/3 the area of the tortilla. It also helps if you soften the tortilla first. Get a wet paper towel, ring it out, and put it over the tortilla and nuke it for 15 seconds or so right before you're ready to roll it. It rolls much easier once it's a little moist, instead of cracking when they're dry.

A tip to getting your burritos to hold together: While rolling, dab the overlapping portions of tortilla with a little water on a barbecue brush, then press the tortilla together firmly (a little help is good, as this can be a three-hand activity). If you will be frying the burrito to make a chimichanga, go ahead and use some beaten egg for an even stronger hold. I try to get a burrito to be as firmly stuffed as an egg roll.

try putting your tortilla on a large hot skillet and turn it when you see it rise - remove after about 30 seconds
put ingredients to the left of center like you are planning an uneven taco
the first side you pull up should cover your ingredients but not reach the other side
fold your sides in and finish the roll
place seam side down back in the skillet for about 45 seconds and repeat on other side
top with salsa (if desired) or Serve as is and that last step adds great texture plus holds it together

alternately, you could go to a taqueria. those people are professionals.