Your sketch is definitely leaning towards punk loli rather than goth loli. That being said you'd probly be okay with combat boots or other western goth footwear (as long as it isn't really fetish-y) in lieu of mary janes. Avoid shiny fabrics and definitely do some research into the fashion if you're wanting to get into it seriously. Personally I think if you can't afford to treat yourself to spendy lace it's probly better to go with ruffles.
Here's a site I found to be very informative:http://www.lolitafashion.org/index.php
points of note:
lolita styles http://www.lolitafashion.org/styles_list.php
anatomy of a lolita outfit http://www.lolitafashion.org/anatomy.php
here's a tut on how to mod a regular collared shirt. I believe she did this all by hand.http://community.livejournal.com/egl/979550.html
here's a couple for bloomershttp://community.livejournal.com/egl/4904975.htmlhttp://www.antipope.org/feorag/gosurori/bloomers-pattern.pdf
you can even simplify that more by using a long rectangle instead of an arc. For a very simple petticoat you can do two to four layers of tulle with a layer of muslin or broadcloth underneath to protect your legs from the scritchy tulle. Use the heavier tulle for your petti since it has better poof.
Also for the second shorter gathered skirt you can make a second skirt that's half as long as the first and attach it to the same waistband as the longer skirt then pin up the center.
here's a more complicated petticoat tutorial:http://community.livejournal.com/sew_loli/682471.html#cutid1