If that is the case, part of the problem is your equipment. Radioshack type soldering irons have tips that do not tin well. So the heat transfer is very poor. It balls up on the tip. Also, if the solder does not "stick" to the object, then you have "wetting" problem. Also, at that point, flux, which is the resin core, has completely evaporated. So there's no wetting action. Solution to this is fairly simple actually.
First, get a good iron. It doesn't have to be adjustable but you have to get one that does NOT have a shiny tip. It needs to be dull silver color. These will wet well and tin well.
Second, if you end up in a situation where the solder does not flow to the object, then remove the existing solder by using "wick" type thing. Then use a thin rosin core solder and use just enough. It will flow nicely then.
Lastly, this has more to do with technique, than equipment. It's pretty much impossible to describe this in text other than to say you need practice and experience. (which doesn't help...)