Conventional timing light with coil on plug setups

How are people using a conventional timing light on an engine that has a coil on plug set up? Am I right in thinking that you would just buy a lead from the shop and then use this as a bridging tool so the timing light has somewhere to clamp to. Or are there new systems that can pick up on the signal wire to the coil?

Either a extension lead from the coil to the plug, or picking up the signal from the coil lead on a sequential fired engine will work with most "dumb" timing lights, some of the timing lights that have the adjustments will not work properly picking up from the signal on the coil lead.

I use this:

http://www.amazon.co.uk/Gunson-77074-Spark-Extension-Tester/dp/B003AMXBM4/ref=sr_1_fkmr0_1?ie=UTF8&qid=1439541284&sr=8-1-fkmr0&keywords=ignition+extension+HT+lead

Never had a single issue with the timing light picking it up nor the RPM pick up on my Innovate LM2

Cool. Thanks for the info guys.