Breeding dahlias has some similarities to New Year resolutions. We resolve every year to take lots of pictures, to label the pictures and to record information accurately on our paper records that are later incorporated into a spreadsheet.
(1) I will take more pictures. Cell phones have made a big difference as it is with you at all times. No excuse that the camera is in the house.
(2) I will take a picture of the plant tag and/or the flagging tape record. Yes, old age means difficulty getting down onto the ground and finding the plant tag put into a difficult place by some earlier version of myself. A picture of beautiful flower is no good unless you know it's identity.
(3) I will not allow the paper record to get wet and become illegible before I transcribe it to the spreadsheet.
(4) I will not use the same identifying number for two different seedlings.
(5) Lots more but you get the idea. 
2025 seedling about 3 inches in diameter and is about a 4th generation seedling.