Up and Down
All too often I hear students practicing their scales in the method listed above. Up and down, up and down. In the music we hear, the scales are rarely used that way. It's the equivalent of learning to paint using the same color combinations over and over. Aside from trying to getting familiar with the scale and trying finger exercises, scales shouldn't be practiced this way. Once you learn a scale and and committed it to memory, you should be practicing it in other ways.
Patterns
One thing that happens a lot in music is patterns. Music is filled with musical patterns repeated at different intervals and different rhythms. Once you learn the fingering for a scale, it's time to try a couple of patterns and play those through the entire scale. There are innumerable combinations but I'll give you a couple of starters.
1. 1-2-3-1, 2-3-4-2, 3-4-5-3, etc. - this is one of the most well known patterns. It's used in pretty much every type of music. It's simply taking three notes of the scale and then returning to the first note. You then take the next note in the scale and use the same pattern. Remember this can be applied to any scale, including pentatonic scales. The idea would be the same but the 'number of the note' would be different. For example a minor pentatonic would look like this: 1-b3-4-1, b3-4-5-b3, etc.There are also a million variations on this.
2. 1-3, 2-4, 3-5, etc. This is essentially the scale in thirds. Any and all intervals should be done here. Remember to do the intervals backwards too. Eg. 3-1, 4-2, etc.
3. 1-3-5, 2-4-6, etc. This pattern outlines all of the triads in the key. Try to identify the triad as you play it. Also try different patterns within this pattern by jumping from different triads. Eg. 1-3-5, 3-5-7, 2-4-6, 4-6-8, etc.
Rhythms
Another important aspect of practicing scales is rhythm. First of all, your scales should be practiced with a metronome. You will also want to practice them with drum beats and rhythm tracks. When practicing with the metronome, start with just playing through the scale like you normally would but using different note lengths. Start with a slow speed using eighth notes. Work up speed gradually. This is the best way to get speed in your playing. Next, try triplets, then sixteenths. Then try swing eighths and then swing sixteenths. Then you can try combination of different values eg. eighths with triplets.
Dynamics and Phrasing
Another exercise is to play the scale using different rhythms but also to incorporate dynamics and phrasing. For example, play in eighth notes but accent certain notes. Start with one accent on the beat, and then try accents on different notes in the bar. Also, try different phrasings, ties and slurs.
Changes In Time
One thing jazz musicians will do will go through the changes in a song, playing the relevant scale for each chord in time. It doesn't have to be a jazz tune to do this. You could take the circle of fifths and play one scale per bar. A great exercise that helps ingrain your scales is to play a continuous line through a set of changes, just playing the scale for each chord. For example for the first bar you would play a C major scale and then in the second, you would play the G major, without stopping in the middle of the phrase to start at the root. Try to keep this going as long as you can through a set of different keys.
Making Music
One of the best ways to learn how to use your scales is to just try and start 'making music' with them. That means just taking the scale, play a phrase, and then try and play the next logical phrase. Of course, the 'next logical phrase' will mean something different to everybody. Whatever style you're into, or what you're trying to accomplish, you want to have your music have some sort of logic to it. Musical language is much like our own language, it follows a lot of the same general rules. First of all, we speak in phrases. That means making a statement, taking a breath, then making a new statement. Try and make your musical phrases breathe, just like the way you speak. Make sure you try different octaves and fingerings. Also, incorporate different dynamics and articulations for each phrase. Make the phrase come alive. At this point we're just trying to play one phrase after another in a logical way.
Bringing Life Into Boring Old Scales
There are many more avenues to take with this but keep it basic at the beginning. Incorporate one or two of these exercises into your daily practice. Don't do them all at one sitting. You don't need to practice these for hours, as long as you're consistent. By practicing these basic exercises and incorporating them into your daily schedule, you'll find your playing, phrasing and improvising taking on a whole new life.