Of all the sounds that are used in the German language, the soft “ch” definitely is a tricky one and many non-native speakers have difficulties with it. That’s also why the word “Eichhörnchen” is often perceived as one of the hardest German words to pronounce. Here’s a tip that might help you:
Say “j” (like in the English word “yes”) or a word that begins with a “j”, like “ja”.
Try to stretch it: “jjjjjjjjj”. “jjjjjjjja”. I’m sure that works great!
Do that a few times and concentrate on what your tongue is doing. The tongue’s position is exactly the same for “j” and “ch”!
Now go on and do these exercises again, but this time whispering! Say “jjjjjjjjj” very quietly (voiceless) as if only the person next to you is supposed to hear it. Does it sound like a “ch” yet?! 
Practise with other words. Here are some examples:
ich - mich - weich - leicht - Milch - euch - wichtig - Brötchen
Now, can you say “Eichhörnchen”? 
Hope this helps!
Versuche einmal, mit Wasser zu gurgeln, wie nach dem Zähne putzen - wie fühlt sich das im Mund an? Was macht dein Gaumen, was macht die Zunge?
