Quick answer: Cap the max size, use platform compression, disable mipmaps where not needed, and disable read/write unless required.
Texture import settings bloating the build are wrong per-texture options. Here is how to fix them.
How to fix it
1. Cap max size and compress
Set each texture's max size to what you actually display and use platform-appropriate compression. Importing textures at source resolution uncompressed is the main cause of bloated build size and memory.
2. Disable mipmaps where not needed
UI and 2D textures shown at a fixed size do not need mipmaps, which add memory. Disable mipmaps for those, keeping them only for textures viewed at varying distances where they prevent shimmer.
3. Disable read/write when unused
Read/Write Enabled doubles a texture's memory by keeping a CPU copy. Disable it unless you read the texture on the CPU at runtime. Most textures do not need it, and leaving it on wastes memory.
Catching the ones you can't reproduce
The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.
Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.
This is where a tool like Bugnet earns its place. Its SDK captures every Unity error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.
A crash you can name from its stack trace is a crash you can usually fix in minutes.