A familiar clean blanket or small piece of existing bedding may make a new resting place more recognisable, provided it fits without blocking the entrance or reducing usable space too much. Use something the cat already rests on rather than adding strong fragrances intended to make the bed attractive. Keep the arrangement simple and check for loose threads, ties or fabric that bunches under the paws. Familiar bedding cannot compensate for a bed that is too small, unstable or badly positioned, so review those basics too. Allow the cat to approach and leave on their own. If the bed has a specific cushion or ventilation arrangement, follow the manufacturer's guidance before adding extra layers. The purpose is to offer continuity within a new option, not to pack the space so tightly that a previously roomy bed becomes awkward to enter or turn around in.
Familiar does not have to mean freshly laundered. Use bedding in a clean, usable condition that retains its normal household scent, and wash it when needed rather than adding perfume to imitate familiarity.
For product comparisons alongside this advice, see Velvet Nest and Silver Velvet Nest. The details below explain their sizes and uses.
Further reading: cats.org.uk.
Velvet Nest
Silver Velvet Nest
AeroMat Chill Pad