Here are two ways to avoid potential problems
Cutting the First Stripe
The method of “cutting” the first stripe, used when a flag has been folded many, many times and is now stretched out to where it will not end up positioned properly for the tuck at the end, creates a very small initial triangle helping create more cloth for later folds.
Here is what the flag looks like before the triangle folds. The small fold to the left is only to show the two horizontal folds.
Pulling the Inside
At the last fold into the blue, which should look like the picture below, if the tip does not fall into the space within the two lines, it may be difficult to tuck at the end of folding.
If the tip does not fall in between those lines, back up one fold, pull the inside folds forward and continue. If the tip comes nowhere close to the blue, as pictured below right, accomplish the same procedure, without backing up a fold.
After finishing the triangle folds, make the last fold at an angle to give the right corner a little more cloth to tuck. It works very, very well for most every flag.