I'd like to improve my camera skills and rely less on Photoshop post-processing to fix problems
If you're shooting with a tripod, there's no reason why your pix shouldn't be pin-sharp. Stick to f11(ish) to get the best out of your lens, with whatever shutter speed is required. That is: it's the
quality of the light that counts, rather than the
quantity. If your exposure needs to be half a second, that's OK. And bring the ISO right down to the minimum; the pic you posted was either soft, or noisy or slightly out of focus (or maybe all three
)
A table-top still life is a very controllable situation, with nothing moving... so these should be the sharpest pix you ever take (and require next-to-no PP)...