What type of diagrams can I create for the design phase?

I am working on a project and i have to create some diagrams for the design phase of SDLC (class diagrams, sequence diagram, dfds etc) i wanted to ask what sort of design diagrams can i include for a web development project? I dont think i can include class diagrams as this is a web related project. Can I include sequence diagrams and Data flow diagrams? Are they a part of the design phase?