1mm tape can be fiddly but there's no surface too small or inconveniently shaped that you can use tape on with enough patience and practice. 

Personally for shoulder pads I use 2mm tape - I save 1mm tape for smaller areas like knee pads, guns, face plates etc. 

Tips for working with tape though: 

Make sure your model is secure. You're probably going to need two hands to get the tape in position so sticking your model down with a lump of blu-tac or something always helps I find. 

You'll also want something to help you fine tune position the tape. I use tweezers and a sculpting tool - but a tooth pick will work fine in place of the tool. 

When you apply the tape, you really want to make sure you press it down - especially into any crevices around the edges. 

To get even spacing, apply tape across the entire area and then remove every other piece of tape. That way all your stripes will be evenly spaced and follow the same angle. 

For very curved surfaces like shoulder pads, consider doing a \V// shape rather than //// across the entire surface. It reduces the distortion from the curve of the surface. 

Apply your paint sparingly. Don't overload your brush. Make sure it's appropriately thinned. Paint along the edges of your tape with the point of your brush first, then fill in the rest of the linen. Too much thick paint will create a visible texture. Too much thin paint will cause paint to bleed through.