To decorate a one-bedroom apartment on a budget, begin by decluttering and organising the space to create a clean and uncluttered environment. To save space and add storage, use multifunctional furniture such as a bed with built-in drawers or a sofa bed. To create a cohesive look, choose simple and inexpensive decorative elements such as wall art, throw pillows, or curtains in a coordinating colour scheme. To create a warm and inviting ambiance, use lighting such as floor lamps or string lights. Finally, to save money and add a personal touch to the space, consider repurposing items or using DIY hacks.