Here is the best advice that I would suggest for proper web design and proper search engine optimization.
1. Always think “architecture”. For example if you have a family of 10 and you live in a studio apartment the “architecture” is wrong (in most places 🙂 ). You need the appropriate number of bedrooms and bathrooms in order to function as a family. Your website works the same way. If you have let’s say 5 related services or products you cannot effectively “jam” them all on one webpage. The best solution is to create the “appropriate number of bedrooms” so the architecture is sound.