Press leaves for paper projects
Thin leaves can dry flat between absorbent layers. The main task is removing moisture, not simply compressing the shape.

Collect a small suitable selection
Choose intact leaves from a permitted source, ideally without rain or dew on them. Take only what the project needs and leave protected or unidentified plants alone. Thin leaves are easier for a first attempt than fleshy ones. A thick stem may imprint neighboring layers and should be considered separately.
Lay the collection flat promptly rather than leaving it crushed in a bag. Record the plant and date on a separate note if useful. The pressed shape may be harder to identify later. Keep the writing beside the material rather than using a strongly colored pen directly on the leaf.
Build a simple book press
Arrange leaves apart between clean absorbent paper layers. Glossy coated paper absorbs poorly and is unsuitable. Keep the leaf surfaces from overlapping. Close the layers carefully so the tips do not fold, then place them inside a suitable heavy book with additional protection for its pages.
Do not use a valuable book: moisture and plant pigments may leave marks. More books on a level surface supply pressure. Keep the stack dry and stable. RHS guidance allows several weeks for book pressing depending on material and conditions; actual dryness matters more than a promised finishing date.
Check without tearing the leaves
Inspect carefully and replace damp absorbent layers when necessary. Open from one side rather than pulling at a stuck leaf. Soft, damp material needs more time. Fully dried leaves may be brittle, so support the whole surface instead of lifting by a single tip.
Store finished leaves flat between clean paper in a dry folder. Use them for cards, collages, or framed arrangements. Varnish is not automatically necessary and may change color or transparency. Test adhesive or coating on a less important leaf. Discard material with suspicious odor, mold, or deterioration during drying and clean the work area; covering it later does not make it suitable decoration.