Herbal magick can be a good source of curse spells, though finding some belladonna may not be that simple because it is poisonous.
Dried belladonna
A black candle
Metal filings or flakes of rust
A small bottle
A single sewing needle
Light the black candle and watch the flame for a few minutes while the wax starts to melt. Focus your thoughts on your target and why you want to place this curse spell on them.
Put some bits of rust or metal in the bottom of the bottle along with the belladonna, and then drop in the sewing needle.
When the wax has started melting pick up the candle and drip some into the bottle. Try to fill it at least a third full (use a small bottle to keep it simple). It should cover over all the contents to keep it in place, though the sewing needle can still stick out of the wax. Say the words, “Poison you” five times and put the lid on the bottle.
Bury the charm in your yard and it should start to work in a few days.