I find that by sewing my best 1/4 inch seam AND pressing well will give me the right measurement. I use a lot of starch on my strips so they are not so 'wavy' when going under the needle. Also, when I cut, I make sure that the line on the ruler sits fully on my fabric.
If you are consistent, your project should look great regardless. If your giftee doesn't like it, I will love it!