A few well-chosen and well-placed patches can personalise your leather-wear in a cool way, but too many can spoil the effect entirely. A huge selection of patches are available from biker jacket retailers and online suppliers, so there's a patch with a logo, saying, joke or image to suit most tastes. However, think carefully before you add any patches. No matter how you attach them, chances are they will leave some kind of mark on the leather if you ever remove them. Plus, if you won't be happy sporting a Mickey Mouse patch 10 years down the line, you're potentially ruining expensive leather-wear that could otherwise last a lifetime.
Find the right thread with which to sew on your patch. Cotton thread will rot over time because of the tannin in the leather, so opt for a polyester or nylon alternative. Choose a thread that is the colour, or close to the colour, of the border of the patch, or a clear thread.
Remove the lining from the leather garment if it is removable. If it doesn't have a removable lining, remove a few stitches to get temporary access behind the lining in the location where you wish to place to patch. If you do not remove the lining, the stitches you make to sew on the patch will hold the lining to the leather where the patch is sewn. To ensure the lining will be in the correct position after the patch is sewn on, stretch the leather and lining out as much as possible and keep the lining smooth. Check the position after the first few stitches and unpick and start again if the lining is out of place. You don't want the lining to tear or to be rucked up uncomfortably around the patch when you wear the garment.
Stick the patch where you want it with some double-sided sticky tape. Pull the sticky tape away after you have sewn around one-third of the patch.
Sew on your patch with a heavy-duty needle -- a curved carpet needle is best -- and a thimble to protect your thumb. Leather is thick and difficult to get a needle through, so a thimble allows you to push firmly on the end of the needle. Sew a slip stitch up through the border of the patch and back down through the leather just outside of the patch, keeping stitches close together. This is the most secure method and will keep the outside of the patch flush to the leather as well.
Start and finish your stitches on the inside of the garment so that any tie-offs and end bits of thread don't show on the outside.
Some patches may have a self-adhesive backing. This will probably not keep your patch in place indefinitely, but will hold the patch in place while you sew.
Glues and iron-on adhesive patches are not advisable for leather. Glues tend to leave residue or pull some surface leather off on removal, while the heat used with iron-on adhesive patches can ruin leather. Sew iron-on patches to leather instead.