Are there any tricks to keeping custom weapon sprites aligned with the center of the screen?

[Mr. Freeze]

See title. 

My fear is that I'll design something cool-looking, only to realize too late that it appears to be aiming downward or upward of where it should be. 

[Doomkid]

I suggest referencing the angle of existing sprites that have an appropriate angle while designing your own custom weapon. I've seen some in the past that suffered from bad perspective and it's a shame to see cool concepts messed up by that simple yet important aspect of the design.

[Dragonfly]

How are you designing it? If we're talking about by-hand sprite work, it'd perhaps be best to work to a vanishing point. If it's a 3D model, then it's less of an issue as you can try a few times to get the angle spot on. :)

 

Referencing the stock weapons as Doomkid suggests is also a great idea.

[Kappes Buur]

I pulled together Eriance's (Amuscaria) tutorials from old ZDOOM forum posts.

They might be of assistance.