I have knitted my entire life...I don't even remember learning and have knitted HUNDREDS of sweaters, not to mention afghans, hats, scarves, etc. I always have about 15 projects going. I knitted a sweater back in the 80's and now it fits me again! My dog also has a hand made sweater......I would certainly rather make hers than buy them.
There are TONS of sites to help you with your tension' I was a tight knitter and really had to work at making my stitches more loose. Find some free patterns for dishcloths and practice with them.....mistakes won't really matter. I prefer the handmade ones over purchased, and have made my own shopping bags, prefering them over the plastic or even the reuseable canvas ones.
buying is much quicker, and cheaper even here in the states, but there is a great feeling in creating your own. Knitting also helps keep my hands busy when in front of the TB, so I am less likely to snac, and hand made items make great gifts!