There is no hard and fast rule for when to change sheets, other than changeable and wash linens when they are dirty. Changing your sheets once a week is recommended to keep your bohemian bedding in good shape. Those with allergies benefit are often washed.
Remove bedspreads, bohemian blankets and sheets from the bed once a week. Set the bedspread and blankets aside. Place a clean set of sheets on the bed by stretching the mounted down sheets over the mattress. Stop the elastic edge under the mattress. Spread the flat top sheet over the duvet cover so the patterned side is facing down. Align the folded border or blade with the top of the mattress near the end. Smooth the sheets over the mattress so it hangs evenly over each side of the bed. Tuck the overhang on the bottom of the bed under the mattress. Fold overhang on both sides under the mattress.
Spread the boho blankets over the top sheet so that the top edge of the blanket is just below the border folded on top of the sheet. Fold the hem of the blade over the blanket and smooth out wrinkles. Fold the side and bottom blankets under the edge of the mattress according to the same procedure for wrapping the blade. Some prefer to allow felt to hang freely from the sides and bottom. Cover with a bedspread or quilt. Smooth out the bedspread with your hands to remove wrinkles. Wash and dry dirty sheets. Remove sheets immediately from the dryer to prevent wrinkles. Fold and store freshly washed sheets in a dry area until it is time to change the bedding again. Wash blankets and duvets twice a year or when they become dirty.