###Not by the spell
Not by the spell
The spell find familiar does not offer any scaling.
As a Warlock you may choose the Voice of the Chain Master Invocation (PHB p.111), which does not improve the stats of your familiar but adds more usefulness.
###Magic Items
Magic Items
One thing easily overlooked are magic items. Per RAW definition your familiar (a creature) should be able to attune to and use some magic items.
Ask your DM if he is OK with that; I can easily see many DMs not allowing it.
Keep in mind that some limits would be:
- If your familiar has no hands, it cannot wield weapons, wands, staffs or similar items. (But maybe two pair of boots?)
- If your familiar cannot speak, it cannot use command words
For other options, ask your DM
Maybe the DM allows you to use a homebrewed a Feat, Invocation or Magic Item to keep your familiar useful.