SIT (solo independent travel) traveler’s tend to opt for high mobility, low volume & weight luggage because it may have to be transported in a variety of vehicles & conditions. Fashion is superfluous & may attract thieves. 

Typical, backpacker’s packs, rolling luggage, day packs, or a mix. I pulled 1 medium rolling luggage & a medium day pack.  

I modified the day pack: 1) with extra external straps on top to hold rain jacket & vest for my Camino de Santiago’s 600-mile trek, & 2) to hide a money pouch with $5k that even TSA didn’t find when I told
them it existed. 

Efficient use of this luggage space is critical depending on nature & length of a trip. My rolling luggage & day pack combo served well. Also, my day pack was used alone for OVN (overnight) side trips from a base city’s hostel where rolling my bag was safely stored.   Redundancy of 'stuff' is to be avoided,

A. Inventory Page(s):
Overtime, I developed an exhaustive Inventory List that detailed every single item, it's quantity & its specific location in various individual compartments & pockets. Feel free to use my editable Inventory List for your template.    [pplk: Resources: Inventory List]

-- partial view of --

The Inventory List was useful for several reasons 
    1. I knew exactly where each item was, so could quickly find it even in the dark.

    2. I could easily add new items or remove unnecessary items based on a country’s climate, etc. (think southern Mexico vs Antarctica)

    3. I could easily amend Inventory List for each future trip, 

B. OVN Inventory List (overnight). 

I also prepared a special day pack OVN Inventory List for 3-4 day overnight (OVN) day pack-only side trips when everything is either worn, in day pack or strapped on its top. [pplk: Resources: OVN Inventory List]  

OVN Inventory List ensured I did not forget what was actually critical when totally dependent on just a small day pack:  e.g.  3 days of my 'old guy' prescription drugs.