If you're selling a product or service online, having the perfect landing page is the key to pulling in those online sales. Formstack have created an amazing guide on how to create the perfect landing page and how it should look.
All landing pages should have just the right amount of information the customer needs, it can't be too less or too much, has to be just right. It has to have all the key points and needs to look organised so it's easily read. Probably the one of the most important bits is the call to action button which is the next step in selling your product. If the potential customer presses that button you know they have some sort of interest, so make sure it leads straight to the sale page.
Colour is also a massive factor and must relate to the image your trying to give or the product your selling. The average person won't know the psychological and analytical effects behind colours, so do your research into which colour will suit best, it's not about using your "favourite" colour.