I made my glove pattern myself:
First measure the circumference of your hand by running a tape measure around your hand(more loosely than tight). Be sure to run it over the boney structures at the base of the fingers (wich is the widest part above the thumb) Draw a sketch of your hand by drawing around your hand on a paper. Fingers slightly spread so the pinkie and the index finger continue the edge of the hands straightly.
Then you have to widen this sketch to half your hand circumference. The outside edge(pinkie) and the inside edge are parallel from top to the hem. The 3 middle lines of the finger slashes are also parallel. Each finger will be slightly tapered (ladies fingers are usually more tapered). Dont taper the outer edges of the indexfinger and pinky; they stay parallel. My fingers are seperated 1mm at the base and 3mm at the tops. the tops of the middle finger and ring finger will be rounded symmetrically. The outside curves of the pinkie and of the index finger top reach a bit lower This is the inside of your pattern.
Fold the piece of paper along the index finger edge. Copy the lines to the new layer. The starting points of the fingers have to be lowered 1cm for the outside.
The thumb hole and the thumb are the hardest part. Best you copy both from your commercial pattern. For the right placement of the thumb hole look where the different points are positioned when wearing a fitting glove and transfer it to your pattern. In my pattern the hole is located 0,5cm to the inside from the folded edge.
For the traditional three rows of decorative stitching mark a point directly 8cm below the meeting point of the middle and ring finger. Left and right of this point mark two points 1,1cm away. These are the starting points of the stitching rows and the stitching aims straightly towards the three finger slash ends.
now the finger-in-between-thingies (name in english?): On the inside part of your pattern measure the outline of the middle finger from slash end point to slash end point with a band measure. Draw a horizontal 2cm line. On the left end draw a perpendicular line. on this line mark a point 1,3cm below the starting line and connect tho the right end of the starting line. on the vertical line mark a point above the starting line; distance is half your finger measurement plus 1cm (when you measured 18cm the distance will be 9+1=10cm). From this point measure 1cm towards the right. Connect to the right end of the starting line. Mark the tip of the part in the middle of the 1cm line and shape the top pointy. This pattern piece is the same for all the fingers. The individual length will be adapted while sewing.
I´ve sewn this pattern with leather sewing about 1,5mm inside of the edges. Seams to the outside of the glove.