I wanted to make my own suet just because I have never done it before.
All you need is:
Lard 1/2 cup per suet cake
Bird Seed we had chicken scratch its a good mix
Black Oiled Sunflower Seeds
You could cut up some apple in small pieces and add it if you want to.
I used a round meal prep container for a mold but anything plastic would work out great.
We had to buy some lard I have never bought it before everything else we had.
Melting the lard in the meal prep container in the microwave took about 45 seconds but I stirred it a few times.
As far as the quantities of the dry ingredients I just guessed it but used more sunflower seeds.
Combine dry ingredients in a container for mixing then add to the lard stir until all is moistened compact it down with a spoon and freeze.
That is all there is to it.
My Suet holders are HUGE and I guess if you wanted to you could find a deep square container to use for this. Suet spoils in our heat so I figured smaller was better.