Recently, students have been asking several teachers for letters of recommendation, reading them, and then selecting the "best" ones. Unfortunately, this is not a good way to get the "best" recommendation.
Start by waiving your rights to view the recommendation. If you have access to the letters (or your parents have access), the letter is deemed "biased" by the colleges. The admissions representatives know that the teacher had to be careful to write the letter so that you/your parents would not object to any of the information. A true recommendation will provide the good and the areas of improvement of a student. Most students/parents do not want the areas of improvement to be part of the letter because they believe it will decrease the chances for admission.
The next thing you can do is evaluating which teacher(s) who can write your recommendation. Strongly consider a teacher who teaches a class that you may have struggled in. This teacher can probably attest to your determination and commitment to improve your grade (seeking help when needed, doing extra work, etc.). Teachers who teach a class that was easy for you will not have constructive criticism to provide the admission committee.
Lastly, approach the teacher(s) well ahead of time and verbally ask them if they would write a letter of recommendation for you. Do not email them or write a note. Once they have said yes, then write a cover letter explaining why you need the recommendation, the deadline(s), and who to address it to. Provide the teacher with the cover letter, your resume, and addressed, stamped envelopes to the college. Don't forget the thank you note to the teacher afterwards.