Help Jumpseating/ Non-rev To Europe

[Bewise]

I'm going to try and non-rev/ jumpseat out of the US to Europe in the middle of September and head back the middle of October.

I'm trying to figure out what cities are best to fly out of, LAX, JFK in terms of number of flights, days of the week, flights that are usually not full etc. I'm looking at one way on each end, fly into Germany and leave out of Greece, for example.

I'm planning on flying into Germany, travel through Europe and leave out of Greece. I can reverse this or fly into Italy or France, although I would rather not back track.

Any help would be greatly appreciated and I thank you in advance.

I'm a flight attendant