Do not use invisible text or links in your site to boost your website for search engines. The seo expert might try to make text or links hidden to guests but noticeable to find engine spiders. One-way they are doing this can be to make use of white text over a white background. Search engines are now able to quickly detect this kind of conduct, therefore it won't support your website position whatsoever.
Place your keywords in unexpected places. If you're using photos, commercials, design, or other designs of advertising where the programming is hidden, include your keywords inside somewhere. Achieving this gives you an upper-hand, as you aren't pestering your viewers with it, but it's still seen by search engines.