Summarize the following:
If you find partway through applying bleach to your hair that you don't have enough to cover your entire head, it's not the end of the world. If you run out of the mixture but you still have all the ingredients you need, quickly mix this together and then continue applying the bleach to your hair. It shouldn't take more than a few minutes for you to make the mixture. If you need to go buy more ingredients, complete the bleaching process for the hair that you've covered in bleach (allowing it to sit on your hair until it's blonde or until a maximum of 50 minutes have passed whichever comes first). Then at your earliest opportunity, buy more materials and apply the bleach to your remaining unbleached hair. Ideally you've worn old clothes and protected them with a towel. If for some reason bleach gets on something you care about, you can try to remove it using the following method: Apply a clear alcohol such as gin or vodka to a cotton wool ball. Rub the stain and the area around it with the ball; this should move some of the garment's original color over to the bleached area. Keep rubbing until the color has covered the bleached area. Rinse well in cold water. If this doesn't work, you might consider bleaching the entire garment and then dyeing it with a fabric dye in a color of your choosing. If you bleach your hair and after 50 minutes the color is nowhere close to blonde, don't panic. This is a common occurrence for people with darker and/or stubborn-to-dye hair. It may take you a few attempts to get your hair the color you want it. If you need to bleach your hair a few times to get it blonde, be sure to give yourself at least two weeks in between bleachings. After each bleaching, pay close attention to the quality of your hair. If it begins to feel very damaged, you'll need to wait longer before you try again. Your hair should feel fairly healthy before you apply more bleach to it, otherwise you'll risk it breaking off or falling out. After a few root touch-ups you may find that your hair has developed bands of different shades of yellow. You can address the darker bands by applying a small amount of bleach to them and letting it sit for several minutes until the strip of hair is closer in color to the rest of your hair. These bands will generally become much less noticeable once you've toned your hair.

Summary:
Don't panic if you run out of bleach before you've covered all your hair. Remove bleach stains from your clothes. Be patient. Remove darker-colored bands from your hair.