First Impression is Last Impression. As cloths and perfectness are first impression of an human being, Themes are first impression of any blog or website.
Here are 10 Factors that should be noted before choosing any blog theme.
1. If you are professional blogger you should not run behind heavy look of blog. Theme should be so sober as it can be. White color looks more professional.
2. If you can afford use custom design themes. It will take out your blog from the group of “adsense made” blogs.
3. Always have your photo in theme. Either in header (the best) or in sidebar. By doing this your readers do not have to imagine your face and they will get connected to you by mind.
4. Your theme is main cause behind your CTR. You should perform adsense optimization on it.
5. Fonts on your theme should not be so small that everyone have to zoom to read it. Use good contrast in fonts and background color too.
6. If you are using ready theme, remove HTML and CSS errors before using it.
7. Your theme should get loaded within reasonable time else user will close your site before it get opened completely.
8. Avoid using complete flash based themes. Normal themes do perform best in SEO.
9. Display ways to get connected with you in sidebar or footer. Email address, Twitter, Facebook etc.
10. Use big icon of RSS feeds. Add it below each post. Also provide a form to subscribe to email updates.