In the short term, you should tweak your resume based on each job you apply to. For example, if one position you’re applying to seems to weigh a certain responsibility or focus over another, you should be sure your resume conveys your expertise in this area. At the same time, you should be updating your resume with your experience as it develops, adding any new skills you’ve learned, courses you’ve taken or awards you won.
Once you have written and organized your information according to the type of resume you have chosen, be sure to format it according to typical professional standards. You should use consistent spacing throughout, and evenly sized margins on all sides if possible. It’s generally best to stick to your word processor’s default settings, but in some cases, if you shrink the margins on the left, right, top and bottom, this can help buy more space to fit your resume on one page.