When we are suggesting something, we are endorsing it as a promising idea only. There is no obligation on the third party to follow through
Let´s look at how we use the verb to suggest in the context of using a Suggestion Box at work:
Why don´t we (+ verb) have a casual dress day on Fridays?
Have you thought about (+ing) installing water coolers on every floor?
We could always (+verb) offer creche facilities
Couldn´t we (+ verb) do a team building weekend away?
When we are recommending something, we are advising what should be done in a particular situation which would benefit the third party. It holds more weight than suggest and makes the receiver sit up and take note.
Let´s look at how we use the verb to recommend in the context of office management:
I think we should consider (+ noun/ing) opening earlier on Mondays
We might be better off (+ing) outsourcing our manufacturing facility to China
It´s probably worth (+ing) investing more money in advertising
It might prove (+ adjective) worthwhile opening a new office in Chicago
I have a few reservations about (+ing /noun) hiring new staff
I´d rather not (+verb) change the working hours
I´d recommend (+that) that we give a bonus in December
It would be better (+infinitive) to open on Saturdays