No filters, other than a uv filter on the lens of these. All I did was some cropping and straightening on these and on the sunrise there was a sun flare I removed.
This was done hand held with my dSLR and a 35-105 lens
And this one was a sunrise. Handheld again with my 18-70 lens
And this one last night at the Relay for Life. And that's a kite not alien life forms dropping in for a visit. Again handheld with a 70-300mm lens.
Granted I'm blessed living on a lake. In the am I just point east and in the pm I just point west.