Collecting signatures on NRLA Tenancy Agreement & Deed of Guarantee

Other

Using NRLA downloaded AST agreement (shared house) and Deed of Guarantee for a student HMO and would be grateful for any suggestions or lessons learned on obtaining completed documents, specifically signatures, from a group comprising UK and oversees students. The group is geographically dispersed and not all will be in UK before tenancy commences. Complicated by requirements/options available being different for a tenancy agreement and a deed (email/sign/scan, electronic signature, wet, other suggestions please). Many thanks.