Why does the instrumental case feel so inconsistent in spoken Eastern Armenian?

I’ve been stuck on this plateau for months where I can read news articles fine, but as soon as I try to express that I'm doing something 'with' a tool or 'by' a means, I blank on the -ov/-ovv/ov endings. Is there a trick to internalizing these case endings without just rote memorizing every noun? I feel like I'm constantly overthinking the grammar instead of just speaking naturally.