Reveal the word
Inhale and exhale three times, breathing out smoothly. Move the tongue closer to the back of the palate and round off your lips. With this position, breath out as if you wanted to make a soap bubble.
Listen to the word photo in English and the word foto in Catalan. It may help you to pronounce the vowel [o] uttering the first syllable in photo without pronouncing [w]. Look at the video below. Do the same with the word (she) goes in English and gos in Catalan. Warch the video below.
Listen to the word door in English and do in Catalan. It may help you observing the articulatory differences between both o. Watch the video below.