Wrong Approaches to Practice Time
If you plan on practicing whenever you have "spare time", you will rarely practice. There is so much competition for your attention that "spare time" will rarely appear. What you need is a consistent practice routine. You need a set schedule. If you want to learn to play bass well, you need to treat practicing like a second job or like school. Don't treat it as optional. If you are serious about playing bass, don't treat it like a hobby or else that's all it will ever be. Remember to match your actions to your desires. Keep them in line or else you'll be very dissatisfied.
Another trap is to practice only when you "feel like it." There will be times when you have no desire to practice. There may be a lot of them. If you want to learn to play bass well, you have to learn to do it regardless of how you feel. Often you'll find you just needed to get started and then you're into it. Again, don't treat practicing as optional. You go to school or work whether you feel like it or not. You pay bills and brush your teeth whether you feel like it or not. And, you practice whether you feel like it or not. Practice is the only way you progress. Eventually practicing will become a habit if not an addiction. It will feel strange when you don't practice.
Scheduling Your Practice Time Wisely
Now you know not to only practice in your spare time or only when you feel like it. An excellent thing to do is set a specific time each day to practice. Something important to realize is a lot of people sabotage their musicianship just by choosing the wrong time of day to practice! Try to strategically pick a time when you are alert and no one will disturb or interrupt you. You need to give it a lot of thought; most people don't. Examine your typical day-to-day life and wisely choose the times when you practice.
Your practice session is an important appointment between you and your bass that no one else should interrupt. I know avoiding interruptions can be difficult for a lot of people. You need to get others to really understand what you are doing. Even if you are deeply serious about practicing and playing bass well, others don't perceive it that way. To others you are merely playing bass and having fun. People rarely mind interrupting your fun. Unless you explain to them how serious you are about your practicing, they will interrupt you. If possible, explain to the people who often interrupt your practicing that it really interferes with your passionate goal of becoming a great bass player.
Another common interruption is the telephone. Avoid answering the phone. When you do, your 1-hour practice session quickly turns into 20 minutes.
Prepare ahead so you don't interrupt yourself. Go to the bathroom, get yourself a beverage and whatever else you need to do beforehand. Do your best to clear your mind of things before you start to practice.
You won't practice very effectively if you are exhausted. Try to choose times when you are most alert. Avoid practicing right after a meal or just before going to bed if you can. You're better off with less practice time when you're clear-headed and rested, than more time when you're not.
Wake Up and Practice
If you can manage it, I highly recommend practicing first thing in the morning. You will develop a much more positive relationship with practicing. When you practice in the evening, you have to think about it all day. It looms over you. All day you will think, "Will I have time to do it today?" And, many things are bound to occur throughout the day that will eat up your practice time. When you practice in the morning, all day you feel good about having it finished. You will feel positive with your progress. The morning is also good because there are usually fewer interruptions and distractions. The phone doesn't ring too much and there's nothing good on TV! I remember when I was in college I would often get up at 4:30am to practice for a couple of hours before going to class. Learning to play bass or any instrument is always a sacrifice for something else.
Make It a Routine
Once you have your set time and people know not to bother you, you must learn to stick to your practice routine. It may take several weeks to get into the habit of consistently practicing. The beginning is always the most difficult. Most importantly, if you slip, don't give up on your routine. Failing is part of the whole learning process. Just as you are learning to play bass, you are learning how to practice bass.
A common pattern of failure is setting up your practice routine and you miss a day or two and feel like you can't pull it off. Then you give up completely and don't practice at all. What you need to do instead is determine what caused you to fail at your practice routine just as when you run into problems playing a bassline or exercise on your bass. Maybe you set yourself up to fail. Maybe you picked a time you didn't expect a lot of conflicts, but there were some. How can you avoid them? What other time could you choose? Is it you causing the problems? Or is it others bothering you? Maybe you expect to practice more than is really possible right now. Figure it all out and adjust accordingly.
Also, there's nothing wrong with easing into your routine. If this is something new in your life, it will take some getting used to. I often recommend getting comfortable with the every day aspect of a routine first. Practice every day for at least five minutes. If you do more, fine. Once you successfully get the every day part going, increase the amount of time you practice each day. Do that until you get to your goal amount of practice time.
Commit to Yourself
You need to come up with a well-conceived practice plan and stick to it. You can be a great bass player if you do this and focus your practice time on the right things.
You will find it is very easy to let yourself down. When there is no one else to answer to for not doing something, we don't feel the same kind of pressure as when there is. This is one of the many reasons teachers help you progress. You don't want to let them down and they push you. You must learn to live up to your commitments to yourself just as you should live up to commitments you make to others. Don't let yourself down by not practicing. If you want to learn to play bass well, you need to put in the time. If you've read this far, you know it's something you want to do. You can do it with the right plan and commitment.