I'd like suggestions for giving my houseplants a little pick me up

What house plants are you referring to? How old are they? Have the been Re-potted?

Have you tried repotting in new houseplant soil mix? The soil becomes depleted over time.

: )

Try mixing a little 7Up or other clear citrus soda in when you water.

I add a tiny, there is a little 'cup' with my fertilizer, very small, not more than a pinch or two. or you could use a few drops of liquid, in each gallon. The soil will not become depleted this way BUT it will still get overloaded with mineral from the water. So you still have to replace it. BUT I have a dehumidifier in the basement, and save all the "distilled" water that comes from it. I mix the fertilizer with this and thus NEVER have mineral build up in the soil.

I have a gardenia that was starting to turn yellow. I started watering it everyday with leftover coffee (not grounds), mixed with a little water. It is now bright green. I dont know if this is peculiar to gardenias, but it might be worth a try.

Try a little warm water. With just a tiny bit of dish washing liquid in it. ( This is for plants with bigger leaves )Wash underside and top of leaves then dry gently.Gentleness is he main ingredient here. You might also want to transplant in bigger pot with lots of drainage holes. Make sure your pants are getting the right amount of light.

I put my plants in the shower so all the dust etc. gets off then a good dose of fertilizer

How about something like tying a ribbon around the base of the plant or, the flower pot for each season or holiday. You can always change them out whenever. I let my grandkids paint my flower pots and they have fun plus it is always something different. We use craft paints from Wal-Mart. They're as cheap as .50

Try Miracle Gro

Rule of thumb when re-potting plants,the roots need to be gently pulled down and tried,all new soil should be used,fertilizer should never be used until the plant has recovered from re-potting. That adds additional stress to the plant. Houseplant fertilizing generally stats after St Patricks day and ends in the end of September once the plants are not as actively growing.