The best tip I've ever heard was to have a tad fertiliser in the water every time you water the plants. Plants eats like us; a bit at the time. If you only had a meal a week you wouldn't feel so good, even if you had a thirty five course banquet. Plants works in the same way. Rather obvious really, but we tend to think that the soil will work as a larder, portioning out the nutrition evenly. Unfortunately it doesn't do that all the time, and the chance is that you water it out when you overflow the container.
I've been using a mild nutrient solution for two weeks. Have I noticed any difference? Well, the tomatoes has set more and bigger fruits. Now, tomatoes are hungry beeings, so I'm not that surprised. My other plants have not changed in the same obvious way, but they do look healthier. Right now I'm short of grown up plants, but it will be interesting to see how my 'gardens' fare when I've got all my beds up.
And it's time to crank up the pflantzensprüher to hunt thrips again. My chives have turned both curly and bald.