Pronunciation is one of the major problems faced by non-native Indonesian speakers when speaking bahasa Indonesia. This particularly faced by people who are native English speakers or learn English as their second language. One of the reasons of the problem is the fact that English language has a lot of sounds, maybe around 40 consonantal and vowel sounds, while Indonesian language has only around 28 sounds, which might be less than that as soon as the non-native Indonesian sounds are omitted. This might make the native English speaker think too complicated when pronouncing the words.
The English writing system imposes problems too. The native English speakers are, if I may say, heavily trained to read cues based on the position of certain consonants when paired with certain vowels or other consonants. The combination of these letters basically provide visual clues on how the word should be pronounced. Interestingly, for non-native English speakers, the cues might seem to be illogical and definitely inconsistent. However, the popularity of the language creates some kind of understanding among the speakers towards this inconsistency.
Unfortunately, when English speakers want to learn other languages, often other less popular languages which has the same writing system, they will find it difficult to pronounce the words of the other languages correctly. There is some sort of mental system that is already installed in their brains so that combination of letters in the other languages become certain cues on the pronunciation whereas actually the combination tells people to read it the way it is.
Even though there are, at least until now, three ways of how people learn things; i.e. visual, auditory, and kinesthetic, I think learning language should start from listening to different sounds in other languages, getting used to the sounds, and practicing following the pronunciation however difficult or strange it might be. Even better, learners should also try to follow the intonation, because, even though Indonesian language is not a tonal language, tones play important roles in determining the notion of the speaker.