Take advantage of tax laws if you're self-employed. Money saved on taxes is still money saved. You may be able to deduct many of your business expenses (use of your home, use of your car, office supplies, etc.) if you keep good records. You may also qualify for tax breaks, such as deducting your health insurance premiums on your tax return. These laws are in place to encourage commerce and business growth, so don't neglect their benefits especially if you want to make money.
Double check yourself, before you double wreck yourself. Make sure everything you send to a company, whether a résumé, an email or a portfolio, is good to go. Double check your grammar and wording, and for God’s sake use spell check! This is especially important when it comes to the company’s name. Don’t spell their name wrong and be sure to type it how they type it (e.g. Problogger, not Pro Blogger).