If you only bake once every week or two, you’ll be happier storing your starter in the fridge in a covered container.
Once a week, take it out, and feed it.
For a wet starter, retain only 1/4 cup of starter and then feed it 1/2 cup flour and 4 Tbs water.
For a stiff starter, retain a marble-sized piece and add 15 grams (1 Tbs) of water. Mush it up until it's soft and the water has turned somewhat milky in color. Then add 25 grams (2 heaping Tbs or 1 Tbs + 1 tsp) of flour.
Keep it out for an hour or four, and then pop it back into the fridge.
If you’re going to bake with it, make sure to take it out a day before and feed it twice, with at least 8 hours in between each feeding.