I have a lot of trouble staying consistent with anything, especially exercising. But I've stumbled onto a trick that is helping me: my oldest daughter.
Julia is not flexible at all. She's also very tall with long legs, and is becoming a young lady. Since I had started doing Hatha Yoga again, which gives one a lot of flexibility, I decided to have her do it with me in the mornings, so that over time she can gain flexibility, poise, posture and strength. She's such a good sport, she's doing it without complaint, even though it's a challenge for her and means getting up extra early, so she can be ready for school on time.
So now when I'm having a hard time getting out of bed in the morning, I remember that she really needs to do her yoga every day, and that motivates me to get going.