Crating an adult dog gives you peace of mind while you're unable to attend to her while also providing her with a safe den of her own. Crating is based on the key concept of dogs being den animals. The hardest part of the process may be waiting for her to get used to the idea, but a kind, soothing voice and some dedicated patience will help both of you through the process.
Measure your dog's height from the top of her head to the floor and her length from the tip of her nose to the tip of her tail. Crates need to be large enough to accommodate her standing and turning around, but not much more than that.
Choose the type of crate based on the needs of you and your pooch. Metal collapsible crates tend to be the most durable and portable, while fabric crates can be cozy, but are easily destroyed by some dogs.
Place the crate in the room where your family spends a lot of time. Family or living rooms are often ideal locations. If this doesn't work, choose the room where she sleeps or eats.
Add a crate liner or her favorite dog bed to the crate to make it more comfortable for her. The idea behind the crate is to give her her own special place -- a den. It should suit her and be comfortable so she'll willingly use the crate.
Take the door off the crate or secure it open. Let her explore the crate on her own at first. Some dogs will jump right in and lay down, others need a bit more time to feel comfortable with it.
Throw in a few extra-tasty treats such as chicken or a small cheese cube. These tasty tidbits give her a special reason to go in and explore the crate, plus there's the added benefit that she'll associate the crate with good things. Repeat this a couple of times a day until she's going in the crate all the way.
Praise her when she goes into the crate all the way while saying something like "go to bed" or "crate time," and especially if she sits or lies down in it. Repeating the cue of "go to bed" or something similar will help her understand that she is to go in the crate upon this cue. Always use the same cue.
Offer her food in the back of the cage. Again, this will help her associate the crate with good things: food!
Put the door back on the cage once she has gone in all the way and seems comfortable with the idea of eating food and treats within the cage.
Ask her to get in her crate using your chosen cue and give her a special chew toy or treat for while she's in there. Shut the door behind her and do something in the same room so she's not alone.
Leave her in the crate for approximately 15 to 30 minutes. Leave the room promptly while saying "too bad" or something similar if she begins to whine. Return to the room after she's stopped whining for 10 to 15 seconds.
Continue these practices a couple times a day for a few days and gradually increase the amount of time she spends in her crate. Once she's going in on her own and not throwing tantrums, leave her in the crate alone in the room for 30 minutes and gradually increase this amount of time over a few days.