Marvin primarily works by identifying shot information based on the location of markers in a sequence. With correctly placed and uniformly-named markers, you can extract a lot of data that is essential to VFX and editorial workflows. If you need to import every clip from a sequence, without taking markers into account, check the ignore markers box in Marvin's user preferences prior to importing the file.
Editors and assistant editors should identify clips of interest in a sequence by adding a marker. Marker colors and naming conventions should be predetermined and coordinated between the different departments. Markers should adhere to a strict naming convention. For example, if editorial names markers similar to: "ONLINE - Resize/Repo," then VFX should name theirs: "doom_229_016_010 - Green Screen Replacement." Likewise, if editorial reserves the use of blue, yellow, magenta, and red marker colors, then VFX should use white, cyan, green, and black. Maintaining consistency will make it possible for Marvin to correctly parse the data.
Acts or Reels should have different start timecodes. For example, act/reel 1 should start at hour 01 (i.e., 01:00:00:00), act/reel 2 should start at hour 02 (i.e., 02:00:00:00), etc. Additionally, add the corresponding act/reel number to Avid's "Reel #" column for each sequence.
Marvin's goal is to reduce errors and duplicated work, so you should be able to use all of the same prep and turnover sequences, but it's still good to create "work" and "backup" versions depending on what you need to accomplish.
For VFX turnovers, you may need to remove all of the non-VFX markers, ensure that each clip only has one marker on it, and simplify your layers so every marker is on the same video track prior to making EDLs. Additionally, it helps to remove all transition effects (e.g., dissolves, fades, etc), commit multicam edits, and remove match frame edits.