Drupal upgrades from 6 to 8, or 7 to 8
Now that Drupal 8 is approaching 8.5.0 (in March 2018), it has reached a maturity level that makes upgrading to Drupal 7 not an option anymore.
Migrations from other platforms to Drupal 8
Moving to Drupal 8 would be hard to regret with all the new authoring improvements, large user base (less chance for vendor lock-in), long life span, speed improvements etc.
Including domain name reservation and hosting. My provider, since 2000, is Netsor located in Finland.
I'm not a pro, therefore when a pro is needed, design will be subcontracted.
Drupal sites typically can be updated by clients themselves but sometimes clients prefer having me do it, which, of course, is fine.
Translations are typically subcontracted to professionals.
Drupal module programming
Most sites need some module or theme programming. This code usually stays behind the scenes, but I do have a couple of contrib modules published in drupal.org.
Not everything can be done server-side.
I like taking and editing photos. If pro quality is called for, subcontractors will be called.
À la Steve Krug, Don't Make Me Think.
Every Drupal site needs both planned maintenance and quick reaction to security updates.