A good torque wrench will cost you well over $100. This one is ok for the occasional DIY'er--Storm 3T317 - Torque Wrench 3/8-in drive. Range: 20 - 200 in/lbs $24 Automotive Tools and Auto Tools from Tool Discounter
. (14 ft/lbs = 168 inch/lbs--yeah, multiply times 12)
Just don't get a 1/2" drive wrench and try to do a 14 ft/lb torque with it--it'll be too inaccurate at that low range.
With aluminum heads it's really important not to over-torque. That can ruin the threads in the cylinder head or break the seal around the porcelain on the plug. If you use anti-seize, deduct 10% from the spec torque.
I always went by feel. Not anymore. I had one plug loosen and blow out. Thankfully the threads weren't damaged. I'm a torque wrench guy now--even after all those years worth of going by feel.