I am working on a spruce for almost 5 years now, slowly reducing height and width. To become a trustworthy bonsai the foliage needs to be close to the trunk , so the ratio trunk/branches/height feels right in our head. If you look outside you can immediately tell if it’s an old or a young tree. Ask yourself why and look at the branches, trunks and the way they are placed.
A spruce backbuds easily so it’s possible to get the needles closer tot the trunk. But that means years of carefull pruning on the exact right moment.
And please don’t place it inside..
Edit: I leave the wire on almost the entire year, if I take it off the next day ( literally) all the branches will be back to their original position. Horticulturally speaking , any idea why? ( not trying to be a wise nose, but if you understand why trees do what they to you are already one step further )