#1
So me and my friends decided to start a gothic metal band. Only problems are, we dont play it. Our singer was in multiple goth bands so she already has vocal melodies and stuff written. We, on the other hand, are completely lost.

We plan to do a Nightwish/Sirenia type of thing. Our guitarist is 100% thrash, me (bass) is more into technical death metal, and our drummer is more into speed metal. Our influences range, but were just lost at how to write gothic music, as its not a major part of our skill-set.

What are some keys, tunings, chord progressions, stuff like that...that are usually used in gothic metal.

Im the most theory-savvy person of the group, so i can just reiterate what you guys give to me to them.

Thanks.
Equipment:

ESP F104 Bass
Spector Legend 5 Classic Bass
ESP B206SM Bass
Axl Mayhem Fireaxe Guitar
Gallien-Krueger 400RB-III Combo Bass Amp
Gallien-Krueger 115SBX Bass Cabinet
#4
The gothic element comes more so by means of synths/orchestral elements and the vocals. From the perspective of guitar, they are not frequently to complex in terms of riffs. I mean, you can throw down some basic chord progressions with some synth strings/piano going behind it and you essentially have a basic foundation for gothic music in general. Its not a complex style of music for most bands, the reality is it is very lyrical and for bands like Nightwish poppy in a lot of ways.
#5
Just play a bunch of chuggy riffs, hire a fit opera singer and wear plenty of mascara. Add synths to the mix and you've completed the recipe.