A good way to create selections in Photoshop is to use “channel-based selections.”
To create a channel-based selection, go into the Channels Panel. Look through all the alpha channels and find a channel with the most contrast between the foreground and background color. You can then use this channel as a selection to create a mask.
Unfortunately, most people limit themselves to the 3 RGB channels, not knowing that there are 7 others to choose from.
You can duplicate the image you’re working on (Image > Duplicate). Then change the color profile to CMYK (Image > Mode > CMYK) to get 4 different alpha channels (or Lab to get 3 others).
Once you look through all the channels and find the channel that has the best contrasts, duplicate it and make any adjustments it may need.
Then go back to the original RGB image and choose Select > Load Selection and you will see the duplicate file along with the channel you created, select it and press OK to make your selection.