I must say I get good results from just keeping the mixed batter in a plastic bowl (with number 5 on the coding purchased from any good supermarket) covered with cling film in a draught-free place and forgetting it for a day or so. Then when it starts to bubble, feed again and cover with cling film. i found it important to beat the lumps out and mix the dough thoroughly each time. The mix should be a creamy consistency, not too watery. Repeat the third feeding when it starts bubbling. By this time it should smell beery. The timescale depends on the temperature of your room.After the third time, it's ready to divide, use half and feed the other as you require. When the reserved dough starts bubbling, after a few days or a week, its ready to use again. Divide, use one half and feed the other whenever needed.

I've had my failures due to my own fault, too much water or not so good flour but I persevered until I got it right. After all, flour and water ferment don't they - usually.....

Unfortunately it tends to take you over and in no time, you've more batter than you need and a freezer full of loaves.

I have even frozen the starter when I've gone on vacation. Taken it out after a month and after thawing, fed it with flour and water and hey presto! A new batch.

I don't use yeast with my sourdough bread and it comes up fine but it's time consuming. If you like sourdough, it's well worth the trouble. Good luck - I'm sure you'll crack it.