any advice on a standard inc/dec template to follow using any size needle and yarn for a simple v-neck sweater?
I see yarn I want to buy and make a sweater of, understand gauge to figure out the co, but how can I just start knitting a sweater if I can’t shape the neck into a v without a pattern?
I don’t want to just follow patterns only.

I suggest a top down raglan sweater. You can find a basic pattern generator at knittingfool.com, which is like a template in that you input your gauge and measurements into it. For a V neck, don’t join the CO and allow only 1 st for each front to start. Increase at the neck edge every 4th row until your 2 front st numbers equal the sts on the back, then join them. If you want a shallower V, inc every other row and join when you have the same number in the front as the back. This is a very loose pattern, and will give you an idea of sweater construction so that you can make different types of top down sweaters.

I did something similar to change a kind of boat neck sweater into a scoop neck. The way I did it was to work the back first so I knew how many stitches I’d be working with and then decided where I wanted the scoop to start and counted that many inches up from the bottom and began there. For the scoop I bound off quite a number for the bottom of the scoop and then using some math calculations figured out the rest. I looked at the back piece and made a “map” of where I wanted the line to go and then how many stitches I would have to get rid of over how many rows to bring me to that point.

I think you could do the same thing for a vee neck. Decide the line you would like the neck to take by looking at the back, (you want to end up with the same number of rows to the shoulder front and back), count how many stitches from center that will be on each side from your starting point. For instance if you figure you need to get rid of 12 stitches on each side from where you begin the vee to the shoulder, then count the number of rows from that beginning point to the shoulder. Then figure mathematically how many rows you will have between decreases to get there. If it is some easy number of rows to work with, like 36—you would decrease every 3rd row to get you there. If it is not so easy you can still do it and just do the decreases in some sort of reasonable way so that things look nice when you finish. Maybe 2 rows between then 3 rows between all the way up, or whatever works.

If you want software that’ll calc it for you, try this freebie. You input your gauge, the number of rows involved and it’ll tell you when to make decs. (Use the Shaping option.)

If you want to calc on your own, check out Righetti’s book ‘Sweater Design in Plain English.’ She shows formulas on when to make incs/decs on sleeves, necklines, etc.

With KnitComp you’ll often end up with shaping on both the RS and WS whereas Righetti’s use even numbers so they’re always on the same side.

I’ve used both and find them equally useful, esp when changing gauge, designing, re-designing, etc.