I keep doing some things wrong with this Marksman stuff.
First off, my instinct is to hit my Explosive Shot as soon as a mob needs some serious damage. My Explosive Shot button is actually my Chimera Shot button. So this is great on a boss who I have already stung. I slam that home every time it is available. But on add mobs or trash I'm usually not thinking to throw them a sting. That was a dps lose for Survival. So I'm hitting them with my big shot -- except it's really a Chimera without a sting to Chimera at all. Chimera fires off and then I realize it wasn't exactly a big hit. /sigh.
My second thing is I hit Serpent Sting accidentally too much. I hit it when I shouldn't. I do hit it when I need to upgrade my chimera rolling sting on a boss. But I also sometimes hit it and effectively downgrade the sting and waste the overlapped DoT to boot.
Why do I do this with Serpent Sting? Well, as SV I'm good -- very good -- at keeping my Serpent Sting up. As soon as it falls off, I slap it back on. I do this by a little macro trick of not having the button be available until I switch targets or until the duration expires. So I see the button become available again. I don't have this visual aid as MM. I just see it available and want to hit it.
I'm not doing Readiness as well as I could. This is mostly timing and knowing when a heroism will be sneaking in. We're also downing bosses quicker and quicker so it's harder to guess. Clearly I'd like to use rapid fire four times in a fight and manage to get some back to back kill shots. But it's a little bit of an art form and I'm only using finger paints at the moment.
I'm not doing burst damage on adds very well. I had to move backward on the blood beasts. And I felt hamstrung on Putricide adds. Maybe that's just the thing with Marks and if I don't like it on those bosses I should flip to SV.
So last night on Dreamwalker I flipped to SV. And then on the vampire Queen I was MM.