Bookmarking probes
You can bookmark probes if they are on your overview. (assuming your brackets are set to show them) This is useful for making bookmarks on grid quickly.
Set your probe scan range to 0.25 AU and click center on my location in the scan window.
Then hover your mouse in the system map (F9) where you see your probes on the map.
If you now press and hold ctrl you'll see arrow to 'zoom in' with your probes.
While holding down ctrl, scroll down with your mouse wheel to move them closer together. Now hit analyse to move the probes to this location. If you've scrolled down far enough all of them should show on grid. If they don't, adjust by scrolling down even more. If they are too close, scroll up.
You can also move the probes to cardinal locations. Set the probe size to 32 AU scan range and press and hold shift. This allow you to drag around the probes to a grid such as in the image on the right.
Set the probe range to 0.25 AU and start scrolling in again while holding shift on your system map.
Hit analyze and if you've scrolled in far enough, the probes will get on grid on the 6 cardinal positions.
Once you like the locations of the probes, save it as a custom formation with the button on your scan window.
Now when ever you are somewhere where you want a perch, you can launch probes. Hit center on my position, your custom formation and analyze. They'll be ongrid where you can bookmark them for perches.