I need help in landscape photography, help please?

Okay so I am off to Belgium, London and Munich in a couple of days. I need tips in taking landscape photos. I've got a Canon Eos 500D along with A Macro Canon EF 50mm f/2.5 and zoom lens EF 75-300mm. And since I can not afford a wide angle lens, I really need tips on taking photos with the lenses I currently have. thank you:).