Budgets go wrong when they are set after the design. Plan in this order instead.
Start with priorities
List the spaces that matter most (kitchen, master bedroom, living room) and spend more there first.
A typical split
Roughly 40–50% for carpentry and storage, 20–25% for furniture, 10% for lighting and electrical, 10% for painting and finishes, and 5–10% for décor and styling.
Keep 10% in reserve
Site surprises and last-minute upgrades are normal. A reserve prevents stress.
Ask for itemised quotes
A good designer shows material, brand and quantity for every line so you can compare fairly.