Snap on scope help

So I have been using a zues for a lab scope and I’m fairly new to this. I haven’t been able to get a ignition waveform pattern on a lot of vehicles and at first I only had the snap on pick ups and now I have joes pickups and while I have been able to see some waveforms I’m still struggling a little. I came across a video on mechanic mindset where he was using a pico scope doing ignition waveforms using a quarter but he said do not hook the ground up. Has this been my proven problem am I not supposed to be hooking ground up for second ignition waveforms? 

If you are trying to capture Secondary Ignition with a "wand" style probe that you touch to the top of the coil, on a COP coil,
     
it can be very difficult to get a good capture. Some coils are insulated/shielded too well to pick any kind of signal with this style probe. Especially vehicles from the Asian market.
What Voltage and Time scales do you have your scope set to? If you are using this type of probe, be sure to set your scope to a very low voltage range. Start with 1-2 volt scale and adjust up or down, if needed. Start with a 5 or 10 ms screen time. 

If you still can't get a signal, the solution is to lift the coil from the spark plug and install an HT Extension Lead in between the coil and spark plug.
 
Then, use a "clamp-around-the-plug wire" style pick-up. 
   

Alternatively, on 2-wire coils, you can capture Primary Ignition voltage from the control wire. (Be prepared for voltage range of 400 volts.) 

Just to make sure that there is no misunderstanding, NEVER allow the spark of the coil enter your scope.
 

Chad thank you for taking the time to respond. I appreciate it very much. Today I had a Chrysler Pacifica late model cylinder 1 misfire as I was able to get a signal from another coil it didn’t exactly look anywhere near the secondary waveforms I see everyone else get. I did play around with the voltage scale and time this is the second vehicle that I had a dead miss on on the past week that didn’t put out any secondary signals which I deemed bad coils