The site moderators and various Hubbers have posted great tips brink proving your hubs. Do a search for 'flagship hubs,' 'raising your score' and a few other terms. Check your spelling and look for grammar errors (there are good hubs on that as well).
Do your topics appeal to a wide audience or a narrow group of people? Hub hoppers are not likely to rate 'up' on an article with limited appeal, so it may take a while to get a higher score. All hubs take time before their scores go up.
Check for readability - do you have paragraph breaks and section (capsule) breaks, with photos added to attract the reader? I've seen some great writing buried in hard-to-read hubs that needed a boost for visual appeal.
Best of luck - you'll do it!