I’m waiting for someone’s reply to your question, because I have the same question.

Dear all, pronunciation in Spanish is not an issue, because we have few vowels and you can pronunciate approximately, there’s no a fixed vowel sound, i mean, it is a wide range of sounds that can correspond, say, to the sound “a”. Regarding the consonants sounds, i know you, English speakers, might find difficult the “rr” sound or the “j” (as ‘ch’ in loch) but there is no big deal about that, everyone will understand you anyway. The big issue with Spanish are verbs and their conjugation, I know english speakers who cry over the subjunctive mood. Anyway, I will be very glad to help you in any thing you like about my language.
Cheers!

well, three if my apologizing for the mistakes in the other comment counts as one…
the first thing: spanish is a phonetic language, or almost phonetic, because two letters are not pronounced (‘h’ ahd ‘u” between a Q or a G and a vowel (e/i). This should make easier your learning. And then, well, yes, sometimes you probably sound like someone with a speech impediment (lol) and i think that happens with certain sounds (t/d/r/b or v) You pronounce the ‘t’ and ‘d’ sounds with your tongue behind your teeth, we pronounce them with the tonge between our lips (slightly!!!) as in your ‘th’, and regarding the ‘r’ sound, you should place your tonge touching the alveolar ridge, touching i mean strongly
well, i am tad wordy,sorry…