My favorites are anywhere along the river boyne’s tow paths
The hill of slane is nice at sunset and sunrise
Slane bridge about and hour or two before sunset
Skreen Church is super for sunsets
Up around Corstown Lake can be nice
Just get a map and compass. Find what angle the sun is setting at and look at hills and rivers on a map that best suit that angle and try to find locations…..
River Boyne tow path is lovely. Skryne church very nice and there is a big dip in the road in front of it that makes for dramatic effect.
Around ashbourne there are some lovely country lanes (though less than there used to be what with the new motorway). I would visit Robertstown (near donaghmore church) or Harlockstown lane (in Baltrasna, on the way to Ratoath). Should be some nice sunset opps available.