When new domains are purchased or acquired at auction the domain usually ends up in a different registrar account each time... which means if you want to keep track of all your domains you eventually have to transfer the domain to your main/preferred registrar account (usually after the 60 day waiting period).
One thing to add to your "to do" list once the transfer is completed and the domain is in your main registrar... is to verify all the Contacts (Registrant, Administrative, Technical, and Billing) as I have noticed many registrars are not following a standard Contact format. This results in name, address, phone, and/or email errors after the transfer... and this really needs to be kept accurate.
Another item is the nameserver settings. Lately, I have had several domains that kept the "old" nameserver settings (from the previous registrar) even though I specifically checked for this to be updated... and this meant the forwarding of the domains were going through the old registrar. It not only slowed the forward down... but I only realized it after a few months when the forwarding quit working!
So, immediately after a successful domain transfer to a new registrar be sure to verify and update the contact information, nameservers, and other settings to make sure the domain keeps working for you!
Ron