February and March are great times to bring branches of some flowering trees and shrubs indoors to force into bloom. One of the easiest to force, and most cheerful when in bloom, is forsythia.
Cutting branches close to their normal bloom cycle will result in faster forcing time. With forsythia buds swelling now, your success is all but guaranteed.
When the temperatures are above freezing, cut branches that are 2-3 feet long and heavily laden with flower buds. Branches toward the top of your plants tend to have more flower buds than the lower branches. Identify the flower buds from leaf buds by looking for the largest and fattest buds. When pruning the branches, be certain to cut to a bud or side shoot and make the cut about 1/4" above the bud.
Once you get the branches indoors, hold them under water and cut off about an inch off the stem. Then split the bottom of the stem with a knife. Keep the cut ends under water as much as possible. Stand the branches in a vase of water and place in a cool location with low to medium light. Leave them there until they are just about to bloom. Change the water every few days and to keep the buds from drying out, lightly mist the branches with water. If you have a packet of floral preservative or cut flower food you can add it to the water. As soon as the flower buds start to open (1-3 weeks), move the vase to a brighter location where you can enjoy the beauty of spring color. The buds will last longer if they are not placed in direct sunlight or near too much heat.
Other branches including flowering quince, pear, cherry, dogwood, and crabapple can be successfully forced.