The thread is definitely preferable to the powder. I generally buy a supply when (or someone I know) visits Spain. Do not keep it in the kitchen as it will degrade much more quickly. I keep it in a dresser drawer in our bedroom which has no radiator and is kept closed and cool in winter and mildly air-conditioned in summer. It will keep in a jar for a good couple of years that way.
Soaking in a small amount of hot liquid is one way to approach using saffron. The color will dissipate faster. A very small amount of liquid is really all that's necessary. I sometimes do this and then add to olive oil, garlic, and basil and use it to dress roasted peppers. It is very good.
Toasting is sometimes recommended. You really need to know your stove and pan for this, as it is very quick to burn, and at that price....
Oftentimes when toasting is recommended, grinding after is also; if you grind, use a mortar and pestle, I was gifted with a small brass one which does not absorb the flavor/color and allows you to get every last bit out.
However, if I'm short of time and haven't pre-planned, I will sometimes add a few threads to what might otherwise be a serviceable but pedestrian dish. The other night, I had some canned giant beans, sauted with a bit of leek, garlic, a pinch of thyme, a bay leaf that got only about 5 minutes in the pot lest it be too strong, parsley, and a few threads of saffron. Stewed together briefly, topped with fresh bread crumbs with enough olive oil to moisten them, run under the broiler, the saffron made it sublime.
If you find you like saffron, I think it's much wiser to invest in a good jar of the good stuff, try it in different preparations, and sometimes very sparingly. I have been subjected too many times to preparations made where a "single dose" has been purchased and all used, to ill effect. Too much saffron can have an almost medicinal taste.
For those who are interested, the Cornish have used saffron for millenia, apparently it developed as part of a trade between Phoenicians in what is now, basically, Andalucia, and Cornwall.
Some remnants of the use by the Cornish can be found in the area from Mineral Point to Dodgeville, WI, where the lead and later zinc mines attracted Cornish miners. The Cornish use there is primarily in saffron buns, a basic sweet yeast dough with raisins and saffron that you will find in old-time bakeries. In one pharmacy in the area, that still had a working soda fountain, I looked up from my malt and noticed what I thought was (and yes, it was) a one-pound tin that had arrived full of saffron, which was repackaged by the pharmacist in consumer-friendly amounts, and at a very good price, for superior Spanish coupe.