Limit yourself to using a maximum of 2 typefaces at a time. Maybe 3 if it's your birthday.

Limit the number of type sizes that you use. If you're using more than you can count on one hand then you probably have too many.

Limit your colour palette. Be respectful of the established conventions of web design: use colour (consistently) ...

By placing these restrictions on yourself, you'll actually make your job a little easier. The less options you have, the easier you will find it to be consistent.

James Greig.