I always do, but modern plastic tanks mean there’s usually little to see.
Best one was a Defender Tdci that my mate bought. It had been run on cans of cherry juice and generally not looked after, and the fuel filter was completely clogged with slimy algae and general sh1te. Diesel bug, I guess.
Oil filters also worth a look - check for bearing shavings etc. The paper elements make the best firelighters as well.