reflexire verbs and pronoms febles do puzzle me a lot .
I just don't know why and when the pronoms febles should be put before the verbs or after the verbs . is there any rule to master ,please ? mirra 1.enfilar-se. En Pep s'enfila a la perera.
2.omplir-se. la casa es va omplir de convidats.
3.vessar-se. Se m'ha vessat la llet.
ok I can understand the sentences above.
BUT this one ensabonar-se .M'agrada ensabonar-me l'esquena primer. can'tb I say :.M'agrada m'ensabonar l'esquena primer. moltes moltes gracies !! Laura

Question

reflexire verbs and  pronoms febles do puzzle me a lot .  
I just don't know why and when the pronoms febles should be put before the verbs or after the verbs . is there any rule to master ,please ?  mirra 1.enfilar-se.    En Pep s'enfila a la perera.
2.omplir-se.    la casa es va omplir de convidats.
3.vessar-se. Se m'ha vessat la llet.
 ok  I can understand the sentences above.
BUT this one   ensabonar-se  .M'agrada ensabonar-me l'esquena primer.  can'tb  I say :.M'agrada  m'ensabonar l'esquena primer.     moltes moltes gracies !!   Laura

Answer

I hope that this link could be helpful to know where to put the pronouns.
http://www.xtec.cat/~aribas4/llengua/pronoms%20febles/teoria.htm
It covers all the possible cases and I wouldn't have explained it better.
I am not sure whether you are able to understand the full text in catalan.
In case you needed some help or some translation, please, don't hesitate to ask me.
Answering your question: "M'agrada ensabonar-me l'esquena primer." cannot be said "M'agrada m'ensabonar l'esquena primer." El pronom me va darrere l'infinitiu, en forma plena.

It's really common having problems with "pronoms febles". They are some of the most difficult aspects in catalan. Many catalan speakers don't even use them properly. Don't give up! You'll do it well very soon!
Good luck and if you need some help, I would be pleased to help.
Best regards,
Cristina