So you want things that are far away to be out of focus. Cool. The best way to do this is focus closer to you, so that things further away aren't in focus.
But that is impeded by a few things. As things get further from your lens, DoF gets inherently wider and wider, so getting a narrow DoF for far away things means you need to overcompensate by focusing even closer than you actually want.
To get a narrower DoF, you should open your aperture up (just like normal). But open it up more than usual to overcompensate for the distance again. Fully open if you can. The problem then becomes shutter speed; on a sunny day, opening your lens up will overexpose the photo, even at fast shutter speeds.
The solution is to block out light entering the lens with a neutral density (ND) filter. I like variable ones that you twist to adjust between 2-9 stops of light. Then you can play around and experiment.
The last thing is the lens you're using. Getting narrow DoF is harder on wider lenses. If you use a longer lens, you compress the DoF. I actually like long lenses for landscapes – some of my favourite Iceland shots were on a 90mm.
Let me know if I can clarify anything!