Below is a link to some information on pruning junipers. Note that if you cut back to woody stems where there is no green foliage, it will not re-grow from that spot.

Daffodil leaves produce food that is stored in the bulb for next year's flowers. If you cut off the foliage before it turns yellow on its own, you reduce the chances of flowering next year. Once the foliage yellows, cut it down to the ground. You can plant perennials in front of them if you have the space, to hide the fading foliage. Daylilies are one good plant for this purpose, there are many others.
Once the foliage has turned yellow, you can dig up and divide the daffodils, as plants that are in one spot for many years produce more bulbs around the original one. This is a good opportunity to thin out overcrowded clumps, which can start to produce fewer flowers after a while, and replant them in other areas.

Check out the bulb forum for more hints on gardening with bulbs.

Here is a link that might be useful: pruning