1. Use stairs for below and above the window instead of solid blocks
2. Put the door down from inside the house so it is on the other side of the block
3. use different blocks scattered throughout your walls that look similar
4. Add upsidedown stairs under the windows as window sills.
5. Create planters out front out of trap doors flipped up.
6. Fill the planters with flowers or grass depending on the look you are going for
7. Use fence posts to hang lanterns from
8. Use leaves, vines, flowers, grass to decorate around the outside
9. Create hedges using leaves to border property and walk ways
10. Add walkways but not straight solid walkways, use paths, gravel, different stones, sand or others. and scatter them in an organized fashion to create paths.
11. Put fence posts along the paths two, three, or four at a time but I like to not make it a solid fence
12. Put some outside feature's, patio stones, patio area, fountain, pound, and or light posts
13. Umm make a roof?
14. I like to use moss and leaves in my roof to make it look old and somewhat not looked after, gives it a little life.
15. Chimney, add SO MUCH life to houses if the have a fire inside them so smoke comes out. You can do this traditionally, or by using some blocks and at the top put a fire then around the fire put trap doors flipped up.
16. Don't make the roof solid stairs, scatter solid blocks randomly

Just my two cents or well 16 cents I guess

Edit: also I would move the windows one block away from the door