You have to start with a perfectly smooth surface to end up with perfectly painted walls or woodwork. One pro tells PM that sander would be a more fitting job title than painter since he spends so much time pushing sandpaper. Sanding levels outs spackle or joint-compound patches and flattens ridges around nail holes. Sanding also removes burrs and rough spots in your trim.

Sand the walls from the baseboard to the ceiling with fine grit sanding paper on a sanding pole. Then sand horizontally along the baseboard and ceiling. Don’t put a lot of pressure on the sanding pole or the head can flip over and damage the wall. Sand woodwork with a sanding sponge to get into crevices.

Before the pros paint walls, they fill holes and patch cracks with joint compound. But if you paint directly over it, the compound will suck the moisture out of the paint, giving it a flat, dull look (a problem called “flashing”). Those spots will look noticeably different than the rest of the wall. To avoid that, pros prime the walls before painting.

Instead of using white primer, pros usually have it tinted gray or a color that’s similar to the finish paint. Tinted primer does a better job of covering the existing paint color than plain primer, so your finish coat will be more vibrant and may require fewer coats. This is especially true with colors like red or orange, which could require three or more coats without a primer.

Nothing is more discouraging when you’ve finished painting than to peel tape off the woodwork and discover the paint bled through. To avoid the pain-in-the-neck chore of scraping off the paint, do a thorough job of adhering the tape before you start. “Apply tape over the wood, then run a putty knife over the top to press down the tape for a good seal,” a painter with more than 16 years of experience says. “That’ll stop any paint bleeds.”

Use the blue painter’s tape instead of masking tape. Masking tape can leave behind a sticky residue that’s hard to clean off. Plus, paint can cause the tape to buckle or get wavy, which lets paint run underneath it. Painter’s tape can be left on for days (some up to two weeks) and still peel off cleanly. And it stops paint bleed without buckling.

The secret to a finish that’s free of lap and brush marks is mixing a paint extender (also called a paint conditioner), such as Floetrol, into the paint. This does two things. First, it slows down the paint drying time, giving you a longer window to overlap just-painted areas without getting ugly lap marks that happen when you paint over dried paint and darken the color. Second, paint extender levels out the paint so brush strokes are virtually eliminated (or at least much less obvious). Pros use extenders when painting drywall, woodwork, cabinets and doors. Manufacturer’s directions tell you how much extender to add per gallon of paint.

The problem with painting along the edge of textured ceilings is that it’s almost impossible to get a straight line along the top of the wall without getting paint on the ceiling bumps. Pros have a simple solution. They run a screwdriver along the perimeter of the ceiling to scrape off the texture. “This lets you cut in without getting paint on the ceiling texture,” one of our pros says. “The screwdriver creates a tiny ridge in the ceiling, so the tips of your paint bristles naturally go into it. And you’ll never even notice the missing texture.”

Pros don’t use bed sheets as drop cloths, and neither should you. Thin sheets won’t stop splatters and spills from seeping through to your flooring. And while plastic can contain spills, the paint stays wet for a long time. That wet paint can (and usually does) find the bottom of your shoes and get tracked through the house.

Use what the pros use—canvas drop cloths. They’re not slippery and they absorb splatters (but still wipe up large spills or they can bleed through). “Unless you’re painting a ceiling, you don’t need a jumbo-size cloth that fills the entire room,” a pro says. “A canvas cloth that’s just a few feet wide and runs the length of the wall is ideal for protecting your floor, and it’s easy to move.”

It might seem easy to do all the corners and trim in a room, then go back to roll the walls, but don’t. Pros get a seamless look by cutting in one wall, then immediately rolling it before starting the next. This allows the brushed and the rolled paint to blend together better.

Cover your paint bucket, tray or container with a damp towel when switching between brushing and rolling to keep your paint and tools from drying out when not in use.

Don’t bother taping windows when painting sashes—it takes a long time and paint usually ends up on the glass anyway. Go ahead and let paint get on the glass. Once it’s dry, simply scrape it off with a razor blade. The paint peels off in seconds. “Just be careful to not break the paint bond between the wood and the glass,” a pro cautions. “Otherwise, moisture can get on the wood and cause rot.”

The “same” color of paint can vary between cans. “That difference can be glaringly obvious if you pop open a new gallon halfway through a wall,” a retired painter tells PM. To ensure color consistency from start to finish, pros mix their cans of paint in a 5 gallon bucket (a process called “boxing”).

Some pros then paint directly out of the bucket. This eliminates the need to pour paint into a roller tray, though the heavy bucket is harder to move.

Whether you buy cheap or expensive roller covers, washing them before their first use gets rid of the fuzz that inevitably comes off once you start painting. Wash them with water and a little bit of liquid soap, and run your hands up and down the covers to pull off any loose fibers (a practice called “preconditioning covers”). You can start using the roller covers right away—you don’t need to let them dry.