Graveyard Keeper grave scores, cemetery layouts and expansion
A grave's score is limited by the buried body's usable white skulls. Better decoration helps until it reaches that limit; paths, larger structures and the cemetery perimeter add their own rating. Use the 
graveyard planner to compare those improvements and their materials before spending them.
Match decorations to the body's skulls
The burial score is the lower of usable white skulls and the rounded-down decoration total minus red skulls. A fresh 
Body with 1 red skull and 2 white skulls therefore scores −1 without decoration, 2 with three decoration points, and still 2 with ten. Preparing a better body can matter more than replacing its stone.
Wooden grave fence adds 1 decoration point and 
Gravestone adds 2. That pair reaches the example body's limit. 
Marble grave fence II and 
Marble cross each add 5 at full condition, but their extra points would be wasted on the same body.
Condition reduces each piece separately. At 30% condition the marble pair provides 1.5 + 1.5 = 3 decoration points. The pictured burial has four usable white skulls and scores 3, so repairing its decoration would help. 
Priestess' Ring also adds 1 decoration point when it is on the body; it does not add a white skull.
Keep the corpse fresh and the layout legal
Freshness caps the white skulls available to a grave. The game rounds the percentage upward, treats a result above 90 as fully fresh, then otherwise rounds white skulls multiplied by freshness downward. The two-white-skull example has only one usable white skull at 50% freshness.
In corpse preparation, compare the organs and injections first. A grave using the prepared corpse follows later changes to that body. Keeping a corpse on a grave instead preserves that particular burial while you prepare the next one.
Marble flagstones adds 3 cemetery rating without changing another grave's score. The 2 × 3 
Lawn adds 2; the 2 × 4 Lawn adds 3; the 2 × 6 Lawn adds 4. Their footprints matter: a piece must fit completely inside the building plots without overlapping another object. A visible path between plots is not automatically a valid building site.
Compare expansion with perimeter improvements
The 
Graveyard scroll opens the western half. Planning that expansion includes one scroll in the material list; marking the western half already open removes that purchase. Closing it again keeps your planned pieces, but their invalid positions must be resolved before the planner gives a cemetery total.
Repairing the wooden perimeter adds 10 rating. The stone perimeter adds 20 in total, not another 20 on top of the wooden fence. Start from the perimeter you already have so the material list charges only the remaining upgrades.
Larger structures need room and construction work. 
Stone columbarium contributes −6 unfinished and 12 complete. 
Marble columbarium changes from −10 to 20. A 
Wooden prayer station changes from −2 to 2; the 
Stone prayer station reaches 4. 
Flowerbed and 
Lantern are restricted to their prayer-station sites. The 
Trunk uses its own pad and adds no rating.
Exhume a body before removing its grave
A marked 
Gravesite scores 0; a dug grave scores −2. An existing buried grave cannot be moved or simply erased. Remove its fence and gravestone before exhuming the body. Exhumation consumes one 
Exhumation Permission and leaves a dug grave, which can then be filled.
Keep a burial's corpse settings before comparing replacements. Exhuming the decorated burial pictured earlier changes its contribution from 3 to −2, so the cemetery drops by 5 until another improvement compensates for it. Undo restores that exact body and its decorations rather than substituting the next corpse on your workbench.