When I first started altering my clothes I didn't know how to sew. If you think DIY-ing your clothes sounds fun, but don't want to invest in a sewing machine, here's some ideas for you. If you have some ideas that you want to submit, please send them in to firstname.lastname@example.org.
You can do tons of things with fabric paint, even if you don't have any painting skills. What I used to do a lot was completely cover my hands in paint, then rub them all over skirts and pants and other things. It creates a really cool splotchy design. You can also:
Use stencils. You can make band logo stencils to decorate your clothes, or you can use letter stencils to say something. Quoting your favorite bands can be fun too. I once stenciled "Fight War, Not Wars" (from Crass) on the back of a plain red shirt.
Paint stripes all over your clothes. You can draw them on first with a pencil or just do it really sloppy.
Paint skeleton bones on something, like you see on Halloween costumes. (for example, arm bones, leg bones, ribcages, etc.)
Use red paint to make it look like blood. I did this with a Dawn of the Dead mini skirt.
Don't only use paintbrushes. I've used the eraser ends of pencils to paint words. It makes letters look really cool. You can also paint different things to make cool stamps, or you can buy your own stamps. I've used the bottom of a thread spool before as a stamp.
Buy spray paint and splatter it on. With some spray cans you can tap the button just a little and the paint will drip out instead spray.
You can also use bleach instead of fabric paint, but be careful. If you use a lot, your clothes will eventually fall apart. Also, not all fabrics can be bleached.
Print out random shapes and cut them out to make stencils. This is really easy to make a skull and crossbones design.
Here are some examples of fabric paint ideas:
You can use yarn to create awesome designs on your clothes. Just buy a really big needle, thread it with some brightly colored yarn, and start sewing. Here are some examples:
There are a million things you can do with big band shirts without sewing them. I'm actually not too good at this, but here are some other sites that have some great t-shirt DIY ideas:
WhatTheCraft.com has a great no sew halter top tutorial
Generation-T.com has two easy t-shirt projects
OhMyStars.net has at least 15 amazing t-shirt ideas
You can do tons of things with just a pair of scissors. Use fabric scissors, or at least the sharpest you can find. If cutting fabric is difficult, you are using the wrong kind.
Frays-denim is the best fabric to fray. Just cut it and throw it in the wash. But don't try to make the seams frayed. I once slashed a pair of jeans all over the seams with an x-acto knife, and after a while they completely fell apart. I now use patches and dental floss to hold them together.
Slashes-cut slashes in your boring shirt, tights, sleeves, or anything else. This works great with stretch fabrics that won't fray. After you cut slashes all over something, wear a different layer under it. T-shirts and tights can look really interesting this way. You can also cut slashes all over a pair of pants or skirt and wear brightly colored tights underneath. Make the slashes really even and neat, or random and all over the place.