It's important to build your confidence. If possible, use simple English sentence structure that you know is correct, so that you can concentrate on getting your message across.
Try to respond to what people say to you. You can often get clues to what people think by looking at their body language. Respond to them in a natural way.
Don't speak too fast. It's important to use a natural rhythm when speaking English. But if you speak too fast, it will be difficult for people to understand you.
Try to relax when you speak. When you speak English at anormal speed, you will discover that most of the pronunciation skills, such as linking between words, will happen automatically.
Practice wherever you can and whenever you can. Any practice is good, whether you speak to someone who is a native English speaker or not.
Try to experiment with the English you know. Use words and phrases you know in new situations. Native English speakers are more likely to correct you if you use the wrong word than if you use the wrong grammar. Experimenting with vocabulary is a really good way of getting feedback.
If you forget a word, do what native English speakers do all the time, and say things that "fill" the conversation. This is better than being completely silent. Try using um or er, if you forget the word.
Try not to translate from or into your own language. This takes too much time and will make you more hesitant.