Adobe Illustrator defaults to hiding the grid behind your artwork. If you are working zoomed in a lot (like I am for pixelart) and need more precise snapping and a better grid view that isn’t hidden, here is how you do it.

To show and hide the grid use the keyboard shortcut ⌘ ‘ ( on a pc it is ctrl ‘ )

Align Objects to the Pixel Grid

Illustrator isn’t pixel based like photoshop, so you can’t be sure where your points are placed unless you check the Align New Objects to Pixel Grid on a new document.

Show the Grid Above Your Art

Select Guides and Grids in Adobe Illustrator’s Preferences.

Deselect the Grids in Back option and click OK. (You can also change the size of the grid’s units and how many subdivisions are between each major gridline. I like working with multiples of 8.)

The keyboard shortcut for showing and hiding the grid in illustrator is Command⌘ + ‘ (key to the right of the semicolon).

Snap to Grid

Finally select Snap to Grid in Illustrator’s View Menu