You should very carefully test an upgrade to 4.5 on a separate test copy of your 4.4 community. There are many significant changes in 4.4 to 4.5 and if you use any third-party plugins, themes, applications, translations, etc., things may no longer work, or require reengineering.
Going from 4.4 to 4.6 will be at least as painful as 4.4 to 4.5, likely worse. It will include all of the changes from 4.4 to 4.5 and whatever else has been done since then.
Best practice would be to backup your database and file storage before any upgrade, maintain a testing environment, and validate that the upgrade works as expected in test, that your dependencies work as expected, and that any add-ons you have in 4.4 upgrade correctly, and are functioning in 4.5.
If you'd like to do all that in an upgrade from 4.4 to 4.6, the same recommended practices would apply.