You learn something about Reaktor every day you work with it. What you learned today may be very easy for you, but it may be very difficult for other users or Reaktor beginners. Share what you learned today here, just add a sentence, or two. We will pick up these tips and build a larger tutorial based on it.
On the PC use Ctrl to automatically create an additional input point for a Macro when you drag a wire towards it, on a Mac it's the Command key. This also works with some Math modules and any other module that has '...' on the bottom left.
To modify instrument volume with an LFO, the LFO has to produce AUDIO output so as to avoid annoying sound artefacts (pitch modulation, in contrast, can safely be done by an event LFO signal). Also, it's a good idea to smoothen the LFO signal using an integrator that adjusts it to Reaktor's control rate´(I once found a "Ramps CtrlRate" macro in one of the User Library's instruments to do the job).