There's really not much you can do in this case. Drupal 7 requires fair bit of memory and so do Views, Panels, etc.
If upgrading to a hosting plan where you have at least 128MB is not an option I would at least make sure the following modules are kept disabled:
- Update Manager
- Database Logging
- Field UI
- Views UI
- Panels In-Place Editor
- Any other "UI" module
Do your development locally and use version control & Features to update your production box.