English speakers often prefer to make generalisations, rather than say something is a fact. When you make generalisations, you will sound less sure of yourself and therefore more open to other people's opinions and ideas. Here are some ways to do this.
To show that something is generally true
"I tend to agree with you."
(I agree with most of what you say.)
"I tend to go to bed early in winter."
(I normally go to bed early in winter.)
have a tendency to
"The English have a tendency to drink tea, not coffee."
Note: have a tendency to is used more in written than in spoken English.
To show how common something is
"Generally speaking, more men than women use the internet."
In most cases
"In most cases, wars are caused by land disputes."
In some cases
"In some cases, English beaches are unsafe for swimming."
In a large number of cases
"In a large number of cases, obesity is caused by over-eating."
Mostly, often, sometimes
(These words go before the main verb, or after the verb to be)
"We are mostly concerned with costs."
"They mostly go to the cinema at weekends."
"Eating chocolate sometimes causes migraines."
"He is sometimes difficult to work with."
"English people often complain about the weather."
To be vague rather than specific
You can also use phrases that refer to your personal experience, but which aren't specific.
"I've often found that..."
"I've often found that if you call after 6pm, you're more likely to get through to the boss."
"In my experience..."
"In my experience, the best time to call is before everyone else gets in to the office."
Although you may find it strange to avoid saying exactly what you mean, being able to make generalisations is a speaking skill that will make you sound much more like a native English speaker.