For foam spiders, you can get small foam sheets or pre stamped spider bodies in a fly shop which can be convenient if you have one near by, or for a less money a pack of 30 sheets of 8 1/2 x11" 2mm craft foam in assorted colors for $6 or so from a craft store like Michaels which will give you 2 lifetimes supply of spiders.
I use a razor blade and a straight edge ruler to cut strips for the bodies. I cut them one hook gap wide, using the point of a hook to make little pinpricks to line up the ruler. Once a long strip is cut to the proper width, you can cut the individual strips to length at about 1 /2 to 2x the shank length of the hook. For panfish any type of hook -- standard length dry fly or even heavy wire 2 extra long or 3 extra long nymph hook is fine (the foam will float heavy wire hooks with no problem). A size 10 or 12 is about right-- any smaller and you'll get a lot of fish swallowing them.
Here's a video: [ame=http://www.youtube.com/watch?v=y5JueSrnEj4]YouTube - Tying the Foam Spider[/ame]
For an underbody, the tyer in the vid uses a synthetic chenille, but you can use anything dubbing, yarn, twisted peacock herl or just thread.
For bass you can also use the same foam to make gurglers, cutting the foam into wider strips, by using the hook gap width on the larger size 6 hooks. Here's a step by step:
Tying the Gurgler
You can use a synthetic like cactus chenille instead of winding hackle for the underbody.
For bass, in addition to the woolly bugger, you can use the same hooks and marabou for a simple marabou winged streamer. A simple to use body material is a woven mylar tinsel sold under many names like Diamond Braid, Body Braid etc (about $2.50 for 4 yards), and is available in many metallic colors. Unlike the weighted bugger which will sink on retrieve and is better for fishing deeper, the marabou streamer will suspend in the water column and can be stripped back slowly near the surface. Good color combinations are:
Gold or Silver body, Black marabou wing
Gold body Olive marabou wing
Gold body, Yellow marabou wing
Silver body, White marabou wing
If you want to get fancy, you can add a couple strands of pearl colored Krystal Flash to the wing for a little added bling (about $3.50 a pack), and a topping of a few strands of Peacock Herl (1/4 oz of strung herl about $3).
Here's a vid for a simple marabou streamer: [ame=http://www.youtube.com/watch?v=ny6CC72m2Es]YouTube - Yellow Marabou Streamer.mpg[/ame]
You can also make your own poppers. Probably the simplest way to get started is buying one of these "kits"- popper bodies complete with hooks:
JS Fly Fishing: Rod Building, Fly Tying: Wapsi Foam Popper Bodies with Hooks
To these you can add tailing material, rubber legs etc. Before you tie stuff on to them, you can paint the bodies with acrylic paints, although they should work fine unpainted. After you've cranked out a few, you may eventually want to make your own by shaping corks you can buy in bulk with a Dremel tool.
Here's a step by step-- this one's pretty fancy, you don't have to get this elaborate to catch fish, just an unpainted popper body, a bit of marabou fluff for a tail and maybe a couple of strands of rubber legs should work fine:
http://www.warmwaterflytyer.com/documents/Perfect-Poppers-for-the-Topwater-Bite.pdf
Good luck and keep us posted on your tying!