if you're going to fiddle with your parts, it's important to put them back properly.
a torque wrench allows you to secure fixings to the manufacturers recommendation, not just 'nip it up'.
you don't need to spend a fortune, i procured a couple that cover a good range of torque.
Draper 28757 3/8-inch 10 - 80nm Square Drive Ratchet Torque Wrench by Draper
Link: http://www.amazon.co.uk/dp/B009VYBFBO
and larger
30-210 nm
Draper 30357 Micrometer Adjustment Torque Wrench by Draper
Link: http://www.amazon.co.uk/dp/B0001K9S52
the smaller unit allows access in tight spaces, the larger has a longer 475mm handle to give leverage.
these are tested/certified from new, typically torque wrenches are most accurate within the middle of their range.
to keep them in top condition;
don't use them as a wrench - just a final torque tool.
back off the adjuster when not in use.
keep them warm and indoors - corrosion will damage them.
happy torquing