There is a new tool out there that simplifies scaling of characters to better suit you! It's quite good, and will definitely be using this in all upcoming projects. Sure you could use Adobe Photoshop or Gimp or Inkscape or any other vectory program, but honestly most of the time it's a headache and this simplifies everything. The creator is currently working on clarifying some steps, but for now this is how to get an accurate scale:
1.) Select a good profile-pose of the character
2.) Set the baseline length (editable) to your height converted to inches
3.) Draw your first line through the entire length of the character's "height"
4.) Add new lines, name them, and begin measuring props and clothing! The new length on each line will depict the size of the prop to scale.
He deserves many accolades for making our lives easier
... and by accolades I mean $$ and share this everywhere so that Nifegun is a household name for cosplayers.