Some of this will repeat advice given earlier. For that, I apologize, but I want to get it all into one response.
Interestingly, yes--there are small differences between conductivity between different trees of different species, and even of different sizes. BUT: lightning contains an unfathomable amount of voltage and amperage--any slight difference between conductivity in trees will be unimportant. If the tree is hit, it will pretty much explode on you.
Avoid being the tallest or most obvious thing in the area, and don't stand among them. This includes the "lone pine tree," of course, but also means you should avoid small groves of trees in an otherwise open area: hiding in there puts you very close to a tree that might get hit. As a few of us have already posted, you don't want to be anywhere near a tree that gets hit. There's a powerful percussive shock, and bits of flaming or smoking wood are propelled out of the tree at scary velocities. Additionally, the sap inside the tree instantly boils (which is what helps blow the tree apart), and scalding goo flies out of the tree. Add to that the falling limbs and possible downing of adjacent trees, and your best bet is to avoid trees.
Seek shelter. A rocky outcropping, an automobile, a tent... whatever.
No shelter? Crouch down on the ground, without your hands contacting the dirt. You want a grounding path along your spine (top of the head to balls of the feet), and never give the electricity an option to travel through your heart by touching the ground. Electricity, if given a choice of grounding itself through your shoes or your arms, it's going to choose running down your arms because there's less resistance.
Once crouched, ditch any significant metal equipment you're carrying: chuck it a few feet away. If you're hit, any metal equipment on your body could contribute to a significant burn. Plus, the more metal on you, the cuter you look to a side flash of lightning.
If you can detect a clear pause between flash and boom, the storm is moving away from you, and you can move toward better cover. But wait until there's a definite gap: one to two seconds. Make sure that you're clear on that-- you might confuse multiple strikes, and move into greater danger.
One thing that concerns me is your statement that you can lose track of the weather. Gotta be honest--that's like losing track of your direction. It could be very dangerous-- please make an effort, because few storms sneak up on anyone: they usually announce their impending arrival pretty early. If you're hearing thunder, it's time to move toward safety.
I think that advice is a last ditch effort to get it to run down your leg and away from your heart.
Weather has been a little weird here this year. Is it just me or have we had some very fast moving cells this year and a lot of them? Guess I'll just try to pay more attention to what the sky is doing and continue to hope for the best if caught again. Thanks again everyone.