I have a love/hate relationship with pencils. They're so fun to colour with, and it's really satisfying to see something appear physically in front of you when you're done! But if I don't want white spots, I have to press hard. It then smudges. And makes shading hard. Maybe I need better pencils? I'd feel derpy spending money on new pencils when it'd better be used on other things though..
I know ya said that you'd rather not spend more money... But here's an interesting thing that may be of interest to you: water-color pencils. Although they're still regular watercolor pencils at the end of the day, if you have a brush ,and a little bit of water, you can smudge the marks and turn the entire drawing into a watercolor piece of art work. (Watercolor makes the white marks look attractive or you can keep adding color and the white dissapears). Only downside is that they're a little harder to use (The pencils themselves are the same, but watercolor is difficult and at times unpredictable.), and if you abuse the water it can damage an area beyond repair. You don't necesarily need higher quality paper, as I'm using paper from my sketchbook which is pretty standard paper. The brushes themselves (And the water) can be portable as well, there are unique sets of brushes that you can put water in them so that when you make a stroke they're wet .
I bought a mini kit that includes everything for twelve dollars off of amazon (Including the portable water brush thing):
https://www.amazon.com/gp/aw/d/B001GJ0E2S/ref=mp_s_a_1_3?ie=UTF8&qid=1468997197&sr=8-3&pi=SY200_QL40&keywords=mitsubishi+pencil+water+color&dpPl=1&dpID=51ytpPfbf0L&ref=plSrch(You can check my gallery to see what I did with them.) And despite the fact that the pencils are short, they last a while, since when you brush over colored areas, you realize that the marks are very dense and the color spreads/) Crayola sells a pack of normal sized watercolor pencils as well, and they're pretty good... Also remember, that despite the fact that they only come with 12 colors, by mixing them, you can get a lot of the other colors... (So far I've had a problem trying to get pink and peach.)...
I'm not a sales person I swear. I just so happened to enjoy the watercolor pencils