The monster below is a typical example of a monster with one claw arm and the other a couple of monstrous tentacles and I wanted the design of the piece to be structured as a convincing monster. the sketch may need some work later down the line, but with this quick ink sketch, you get the idea.
When drawing a monster it is perfectly natural to try and make it scary looking, but how do you do this? Well you can look to really simple photos and pictures of insects or animals for inspiration, you can use what you want out of these reference pictures and I like to use a variation on different things, such as a dogs head shape makes a great werewolf, but then if you place that dogs head on a horrible mass of tenteacles and a slimy blog, you have created an original and unique monster, so just go for it!
Now I just mentioned the blob idea, now take that idea and run with it, the quick sketch below was just a quick idea and I didn't think much about it, I just started to draw big hands and then a blob monsters with a tooth loaded mouth and there we go, ideas can just come and you can draw some quite cool stuff if you put your mind to it.
Edit: 19/05/2021 - It's interesting looking back on this post because the way I used to draw back in 2010 to now is way different and my art has improved a lot. Here is a monster sketch I did this morning to show that it is worth sticking with drawing if you love it and get better at it over time.