Correct way to attach speaker wires... Wait, what!!!

All connectors degrade sound. All, regardless of cost. Bare wire is best. Do the comparisons and it is obvious. So, go with bare wire.

1) just clean every so often and no oxidatiobpn issues.
2) or just thin the stripped area - good option

You can buy some very good sounding tinned speaker wire from Duelund. Their 16 gauge stranded in cotton wire.  Makes great speaker cable and costs $10 meter.  It is tinned already.  You can buy it from Parts Connextion if interested. 

The wire of your choice cold welded (method used by Audioquest) to thin pure silver spades.  Tighten down but not to the point that you deform the thin silver spades.  Listen and enjoy!

After doing a lot of testing with different types of power cord and interconnect connectors, I do not actually believe that bare copper against bare copper would be the best solution.  It really depends on what your speaker binding posts are.  Bare copper against bare copper (two different pieces of metal under physical contact) does not really transfer higher frequencies as well.  This is where plating increases the ability for high frequencies to jump from one piece to another (i.e. bare copper against rhodium/gold/silver plating).  The plating just dictates the type of sonic signature you're after.  Gold plated binding posts could be good, but if it's pure brass, then you can probably improve by using a plated banana/spade.

Good point. I’ve been able to tin individual wire runs, stranded or solid core, up to 14 gauge no problem. If you start to get 12 gauge and thicker well yeah not easy to tin.
However, once you strip a speaker cable, outer jacket and insulation, I don’t know of any using gauges any thicker than 10 gauge? Perhaps they’re out there I’m just not aware of them.

I don’t use binding posts, at least I don’t use them in a traditional manner. I just use them for clamping together the runs of the speaker cable and the crossover leads from the speaker. I haven’t had any problem clamping together two 10 gauge wires with a 12 gauge wire with this process.

You see I really do not believe in connectors as I believe they all degrade sound. I do the same thing on the amp end and bypass the binding post simply using them as a clamp for the output wires of the amplifier to the speaker wire.

In the past I have built my own nylon binding posts able to clamp together very large gauges of wire and cabling.

I realize not many people are going to go to all this effort. I’m kind of nuts that way.